--- _id: '13966' abstract: - lang: eng text: We present a low-scaling diagrammatic Monte Carlo approach to molecular correlation energies. Using combinatorial graph theory to encode many-body Hugenholtz diagrams, we sample the Møller-Plesset (MPn) perturbation series, obtaining accurate correlation energies up to n=5, with quadratic scaling in the number of basis functions. Our technique reduces the computational complexity of the molecular many-fermion correlation problem, opening up the possibility of low-scaling, accurate stochastic computations for a wide class of many-body systems described by Hugenholtz diagrams. acknowledgement: We acknowledge stimulating discussions with Sergey Varganov, Artur Izmaylov, Jacek Kłos, Piotr Żuchowski, Dominika Zgid, Nikolay Prokof'ev, Boris Svistunov, Robert Parrish, and Andreas Heßelmann. G.B. and Q.P.H. acknowledge support from the Austrian Science Fund (FWF) under Projects No. M2641-N27 and No. M2751. M.L. acknowledges support by the FWF under Project No. P29902-N27, and by the European Research Council (ERC) Starting Grant No. 801770 (ANGULON). T.V.T. was supported by the NSF CAREER award No. PHY-2045681. This work is supported by the German Research Foundation (DFG) under Germany's Excellence Strategy EXC2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster). The authors acknowledge support by the state of Baden-Württemberg through bwHPC. article_number: '045115' article_processing_charge: No article_type: original author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Quoc P full_name: Ho, Quoc P id: 3DD82E3C-F248-11E8-B48F-1D18A9856A87 last_name: Ho - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 - first_name: T. V. full_name: Tscherbul, T. V. last_name: Tscherbul citation: ama: 'Bighin G, Ho QP, Lemeshko M, Tscherbul TV. Diagrammatic Monte Carlo for electronic correlation in molecules: High-order many-body perturbation theory with low scaling. Physical Review B. 2023;108(4). doi:10.1103/PhysRevB.108.045115' apa: 'Bighin, G., Ho, Q. P., Lemeshko, M., & Tscherbul, T. V. (2023). Diagrammatic Monte Carlo for electronic correlation in molecules: High-order many-body perturbation theory with low scaling. Physical Review B. American Physical Society. https://doi.org/10.1103/PhysRevB.108.045115' chicago: 'Bighin, Giacomo, Quoc P Ho, Mikhail Lemeshko, and T. V. Tscherbul. “Diagrammatic Monte Carlo for Electronic Correlation in Molecules: High-Order Many-Body Perturbation Theory with Low Scaling.” Physical Review B. American Physical Society, 2023. https://doi.org/10.1103/PhysRevB.108.045115.' ieee: 'G. Bighin, Q. P. Ho, M. Lemeshko, and T. V. Tscherbul, “Diagrammatic Monte Carlo for electronic correlation in molecules: High-order many-body perturbation theory with low scaling,” Physical Review B, vol. 108, no. 4. American Physical Society, 2023.' ista: 'Bighin G, Ho QP, Lemeshko M, Tscherbul TV. 2023. Diagrammatic Monte Carlo for electronic correlation in molecules: High-order many-body perturbation theory with low scaling. Physical Review B. 108(4), 045115.' mla: 'Bighin, Giacomo, et al. “Diagrammatic Monte Carlo for Electronic Correlation in Molecules: High-Order Many-Body Perturbation Theory with Low Scaling.” Physical Review B, vol. 108, no. 4, 045115, American Physical Society, 2023, doi:10.1103/PhysRevB.108.045115.' short: G. Bighin, Q.P. Ho, M. Lemeshko, T.V. Tscherbul, Physical Review B 108 (2023). date_created: 2023-08-06T22:01:10Z date_published: 2023-07-15T00:00:00Z date_updated: 2023-08-07T08:41:29Z day: '15' department: - _id: MiLe - _id: TaHa doi: 10.1103/PhysRevB.108.045115 ec_funded: 1 external_id: arxiv: - '2203.12666' intvolume: ' 108' issue: '4' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2203.12666 month: '07' oa: 1 oa_version: Preprint project: - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities - _id: 26B96266-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02751 name: Algebro-Geometric Applications of Factorization Homology - _id: 26031614-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P29902 name: Quantum rotations in the presence of a many-body environment - _id: 2688CF98-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '801770' name: 'Angulon: physics and applications of a new quasiparticle' publication: Physical Review B publication_identifier: eissn: - 2469-9969 issn: - 2469-9950 publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: 'Diagrammatic Monte Carlo for electronic correlation in molecules: High-order many-body perturbation theory with low scaling' type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 108 year: '2023' ... --- _id: '14650' abstract: - lang: eng text: We study the out-of-equilibrium quantum dynamics of dipolar polarons, i.e., impurities immersed in a dipolar Bose-Einstein condensate, after a quench of the impurity-boson interaction. We show that the dipolar nature of the condensate and of the impurity results in anisotropic relaxation dynamics, in particular, anisotropic dressing of the polaron. More relevantly for cold-atom setups, quench dynamics is strongly affected by the interplay between dipolar anisotropy and trap geometry. Our findings pave the way for simulating impurities in anisotropic media utilizing experiments with dipolar mixtures. acknowledgement: "We thank Lauriane Chomaz for useful discussions and comments on the manuscript. We also\r\nthank Ragheed Al Hyder for comments on the manuscript.\r\nG.B. acknowledges support from the Austrian Science Fund (FWF),\r\nunder Project No. M2641-N27. This work is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy EXC2181/1-\r\n390900948 (the Heidelberg STRUCTURES Excellence Cluster). A. G. V. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under the\r\nMarie Skłodowska-Curie Grant Agreement No. 754411. L.A.P.A acknowledges by the PNRR\r\nMUR project PE0000023 - NQSTI and the Deutsche Forschungsgemeinschaft (DFG, German\r\nResearch Foundation) under Germany’s Excellence Strategy - EXC - 2123 Quantum Frontiers390837967 and FOR2247." article_number: '232' article_processing_charge: No article_type: original author: - first_name: Artem full_name: Volosniev, Artem id: 37D278BC-F248-11E8-B48F-1D18A9856A87 last_name: Volosniev orcid: 0000-0003-0393-5525 - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Luis full_name: Santos, Luis last_name: Santos - first_name: Luisllu A. full_name: Peña Ardila, Luisllu A. last_name: Peña Ardila citation: ama: Volosniev A, Bighin G, Santos L, Peña Ardila LA. Non-equilibrium dynamics of dipolar polarons. SciPost Physics. 2023;15(6). doi:10.21468/scipostphys.15.6.232 apa: Volosniev, A., Bighin, G., Santos, L., & Peña Ardila, L. A. (2023). Non-equilibrium dynamics of dipolar polarons. SciPost Physics. SciPost Foundation. https://doi.org/10.21468/scipostphys.15.6.232 chicago: Volosniev, Artem, Giacomo Bighin, Luis Santos, and Luisllu A. Peña Ardila. “Non-Equilibrium Dynamics of Dipolar Polarons.” SciPost Physics. SciPost Foundation, 2023. https://doi.org/10.21468/scipostphys.15.6.232. ieee: A. Volosniev, G. Bighin, L. Santos, and L. A. Peña Ardila, “Non-equilibrium dynamics of dipolar polarons,” SciPost Physics, vol. 15, no. 6. SciPost Foundation, 2023. ista: Volosniev A, Bighin G, Santos L, Peña Ardila LA. 2023. Non-equilibrium dynamics of dipolar polarons. SciPost Physics. 15(6), 232. mla: Volosniev, Artem, et al. “Non-Equilibrium Dynamics of Dipolar Polarons.” SciPost Physics, vol. 15, no. 6, 232, SciPost Foundation, 2023, doi:10.21468/scipostphys.15.6.232. short: A. Volosniev, G. Bighin, L. Santos, L.A. Peña Ardila, SciPost Physics 15 (2023). date_created: 2023-12-10T13:03:07Z date_published: 2023-12-07T00:00:00Z date_updated: 2023-12-11T07:44:08Z day: '07' ddc: - '530' department: - _id: MiLe doi: 10.21468/scipostphys.15.6.232 ec_funded: 1 external_id: arxiv: - '2305.17969' file: - access_level: open_access checksum: e664372a1fe9d628a9bb1d135ebab7d8 content_type: application/pdf creator: dernst date_created: 2023-12-11T07:42:04Z date_updated: 2023-12-11T07:42:04Z file_id: '14669' file_name: 2023_SciPostPhysics_Volosniev.pdf file_size: 3543541 relation: main_file success: 1 file_date_updated: 2023-12-11T07:42:04Z has_accepted_license: '1' intvolume: ' 15' issue: '6' keyword: - General Physics and Astronomy language: - iso: eng month: '12' oa: 1 oa_version: Published Version project: - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities - _id: 260C2330-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '754411' name: ISTplus - Postdoctoral Fellowships publication: SciPost Physics publication_identifier: issn: - 2542-4653 publication_status: published publisher: SciPost Foundation quality_controlled: '1' status: public title: Non-equilibrium dynamics of dipolar polarons tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 15 year: '2023' ... --- _id: '11592' abstract: - lang: eng text: 'We compare recent experimental results [Science 375, 528 (2022)] of the superfluid unitary Fermi gas near the critical temperature with a thermodynamic model based on the elementary excitations of the system. We find good agreement between experimental data and our theory for several quantities such as first sound, second sound, and superfluid fraction. We also show that mode mixing between first and second sound occurs. Finally, we characterize the response amplitude to a density perturbation: Close to the critical temperature both first and second sound can be excited through a density perturbation, whereas at lower temperatures only the first sound mode exhibits a significant response.' acknowledgement: The authors gratefully acknowledge stimulating discussions with T. Enss, and thank an anonymous referee for suggestions and remarks that allowed us to improve the original manuscript. This work is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy EXC2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster). article_number: '063329' article_processing_charge: No article_type: original author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Alberto full_name: Cappellaro, Alberto id: 9d13b3cb-30a2-11eb-80dc-f772505e8660 last_name: Cappellaro orcid: 0000-0001-6110-2359 - first_name: L. full_name: Salasnich, L. last_name: Salasnich citation: ama: 'Bighin G, Cappellaro A, Salasnich L. Unitary Fermi superfluid near the critical temperature: Thermodynamics and sound modes from elementary excitations. Physical Review A. 2022;105(6). doi:10.1103/PhysRevA.105.063329' apa: 'Bighin, G., Cappellaro, A., & Salasnich, L. (2022). Unitary Fermi superfluid near the critical temperature: Thermodynamics and sound modes from elementary excitations. Physical Review A. American Physical Society. https://doi.org/10.1103/PhysRevA.105.063329' chicago: 'Bighin, Giacomo, Alberto Cappellaro, and L. Salasnich. “Unitary Fermi Superfluid near the Critical Temperature: Thermodynamics and Sound Modes from Elementary Excitations.” Physical Review A. American Physical Society, 2022. https://doi.org/10.1103/PhysRevA.105.063329.' ieee: 'G. Bighin, A. Cappellaro, and L. Salasnich, “Unitary Fermi superfluid near the critical temperature: Thermodynamics and sound modes from elementary excitations,” Physical Review A, vol. 105, no. 6. American Physical Society, 2022.' ista: 'Bighin G, Cappellaro A, Salasnich L. 2022. Unitary Fermi superfluid near the critical temperature: Thermodynamics and sound modes from elementary excitations. Physical Review A. 105(6), 063329.' mla: 'Bighin, Giacomo, et al. “Unitary Fermi Superfluid near the Critical Temperature: Thermodynamics and Sound Modes from Elementary Excitations.” Physical Review A, vol. 105, no. 6, 063329, American Physical Society, 2022, doi:10.1103/PhysRevA.105.063329.' short: G. Bighin, A. Cappellaro, L. Salasnich, Physical Review A 105 (2022). date_created: 2022-07-17T22:01:55Z date_published: 2022-06-30T00:00:00Z date_updated: 2023-08-03T12:00:11Z day: '30' department: - _id: MiLe doi: 10.1103/PhysRevA.105.063329 external_id: arxiv: - '2206.03924' isi: - '000829758500010' intvolume: ' 105' isi: 1 issue: '6' language: - iso: eng main_file_link: - open_access: '1' url: ' https://doi.org/10.48550/arXiv.2206.03924' month: '06' oa: 1 oa_version: Preprint publication: Physical Review A publication_identifier: eissn: - 2469-9934 issn: - 2469-9926 publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: 'Unitary Fermi superfluid near the critical temperature: Thermodynamics and sound modes from elementary excitations' type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 105 year: '2022' ... --- _id: '11998' abstract: - lang: eng text: Recently it became possible to study highly excited rotational states of molecules in superfluid helium through nonadiabatic alignment experiments (Cherepanov et al 2021 Phys. Rev. A 104 L061303). This calls for theoretical approaches that go beyond explaining renormalized values of molecular spectroscopic constants, which suffices when only the lowest few rotational states are involved. As the first step in this direction, here we present a basic quantum mechanical model describing highly excited rotational states of molecules in superfluid helium nanodroplets. We show that a linear molecule immersed in a superfluid can be seen as an effective symmetric top, similar to the rotational structure of radicals, such as OH or NO, but with the angular momentum of the superfluid playing the role of the electronic angular momentum in free molecules. The simple theory sheds light onto what happens when the rotational angular momentum of the molecule increases beyond the lowest excited states accessible by infrared spectroscopy. In addition, the model allows to estimate the effective rotational and centrifugal distortion constants for a broad range of species and to explain the crossover between light and heavy molecules in superfluid 4He in terms of the many-body wavefunction structure. Some of the above mentioned insights can be acquired by analyzing a simple 2 × 2 matrix. acknowledgement: IC acknowledges the support by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 665385. GB acknowledges support from the Austrian Science Fund (FWF), under Project No. M2461-N27 and from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy EXC2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster). ML acknowledges support by the Austrian Science Fund (FWF), under Project No. P29902-N27, and by the European Research Council (ERC) starting Grant No. 801770 (ANGULON). HS acknowledges support from the Independent Research Fund Denmark (Project No. 8021-00232B) and from the Villum Fonden through a Villum Investigator Grant No. 25886. article_number: '075004' article_processing_charge: Yes article_type: original author: - first_name: Igor full_name: Cherepanov, Igor id: 339C7E5A-F248-11E8-B48F-1D18A9856A87 last_name: Cherepanov - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Constant A. full_name: Schouder, Constant A. last_name: Schouder - first_name: Adam S. full_name: Chatterley, Adam S. last_name: Chatterley - first_name: Henrik full_name: Stapelfeldt, Henrik last_name: Stapelfeldt - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 citation: ama: Cherepanov I, Bighin G, Schouder CA, Chatterley AS, Stapelfeldt H, Lemeshko M. A simple model for high rotational excitations of molecules in a superfluid. New Journal of Physics. 2022;24(7). doi:10.1088/1367-2630/ac8113 apa: Cherepanov, I., Bighin, G., Schouder, C. A., Chatterley, A. S., Stapelfeldt, H., & Lemeshko, M. (2022). A simple model for high rotational excitations of molecules in a superfluid. New Journal of Physics. IOP. https://doi.org/10.1088/1367-2630/ac8113 chicago: Cherepanov, Igor, Giacomo Bighin, Constant A. Schouder, Adam S. Chatterley, Henrik Stapelfeldt, and Mikhail Lemeshko. “A Simple Model for High Rotational Excitations of Molecules in a Superfluid.” New Journal of Physics. IOP, 2022. https://doi.org/10.1088/1367-2630/ac8113. ieee: I. Cherepanov, G. Bighin, C. A. Schouder, A. S. Chatterley, H. Stapelfeldt, and M. Lemeshko, “A simple model for high rotational excitations of molecules in a superfluid,” New Journal of Physics, vol. 24, no. 7. IOP, 2022. ista: Cherepanov I, Bighin G, Schouder CA, Chatterley AS, Stapelfeldt H, Lemeshko M. 2022. A simple model for high rotational excitations of molecules in a superfluid. New Journal of Physics. 24(7), 075004. mla: Cherepanov, Igor, et al. “A Simple Model for High Rotational Excitations of Molecules in a Superfluid.” New Journal of Physics, vol. 24, no. 7, 075004, IOP, 2022, doi:10.1088/1367-2630/ac8113. short: I. Cherepanov, G. Bighin, C.A. Schouder, A.S. Chatterley, H. Stapelfeldt, M. Lemeshko, New Journal of Physics 24 (2022). date_created: 2022-08-28T22:02:01Z date_published: 2022-08-11T00:00:00Z date_updated: 2023-08-03T13:19:06Z day: '11' ddc: - '530' department: - _id: MiLe doi: 10.1088/1367-2630/ac8113 ec_funded: 1 external_id: isi: - '000839216900001' file: - access_level: open_access checksum: 10116a08d3489befc13dba2cc44490f1 content_type: application/pdf creator: alisjak date_created: 2022-08-29T09:57:40Z date_updated: 2022-08-29T09:57:40Z file_id: '12005' file_name: 2022_NewJournalofPhysics_Cherepanov.pdf file_size: 1912882 relation: main_file success: 1 file_date_updated: 2022-08-29T09:57:40Z has_accepted_license: '1' intvolume: ' 24' isi: 1 issue: '7' language: - iso: eng month: '08' oa: 1 oa_version: Published Version project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: 2688CF98-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '801770' name: 'Angulon: physics and applications of a new quasiparticle' - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities publication: New Journal of Physics publication_identifier: issn: - 1367-2630 publication_status: published publisher: IOP quality_controlled: '1' scopus_import: '1' status: public title: A simple model for high rotational excitations of molecules in a superfluid tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 24 year: '2022' ... --- _id: '11997' abstract: - lang: eng text: "We study the fate of an impurity in an ultracold heteronuclear Bose mixture, focusing on the experimentally relevant case of a ⁴¹K - ⁸⁷Rb mixture, with the impurity in a ⁴¹K hyperfine state. Our paper provides a comprehensive description of an impurity in a BEC mixture with contact interactions across its phase diagram. We present results for the miscible and immiscible regimes, as well as for the impurity in a self-bound quantum droplet. Here, varying the interactions, we find exotic states where the impurity localizes either at the center or\r\nat the surface of the droplet. " acknowledgement: We thank A. Simoni for providing the calculations of the intercomponent scattering lengths. We gratefully acknowledge stimulating discussions with L. A. Peña Ardila, R. Schmidt, H. Silva, V. Zampronio, and M. Prevedelli for careful reading. G.B. acknowledges support from the Austrian Science Fund (FWF) under Project No. M2641-N27. T.M. acknowledges CNPq for support through Bolsa de produtividade em Pesquisa No. 311079/2015-6. This work is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy No. EXC2181/1-390900948 (the Heidelberg STRUCTURES Excellence Cluster). This work was supported by the Serrapilheira Institute (Grant No. Serra-1812-27802). We thank the High-Performance Computing Center (NPAD) at UFRN for providing computational resources. article_number: '023301' article_processing_charge: No article_type: original author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: A. full_name: Burchianti, A. last_name: Burchianti - first_name: F. full_name: Minardi, F. last_name: Minardi - first_name: T. full_name: Macrì, T. last_name: Macrì citation: ama: Bighin G, Burchianti A, Minardi F, Macrì T. Impurity in a heteronuclear two-component Bose mixture. Physical Review A. 2022;106(2). doi:10.1103/PhysRevA.106.023301 apa: Bighin, G., Burchianti, A., Minardi, F., & Macrì, T. (2022). Impurity in a heteronuclear two-component Bose mixture. Physical Review A. American Physical Society. https://doi.org/10.1103/PhysRevA.106.023301 chicago: Bighin, Giacomo, A. Burchianti, F. Minardi, and T. Macrì. “Impurity in a Heteronuclear Two-Component Bose Mixture.” Physical Review A. American Physical Society, 2022. https://doi.org/10.1103/PhysRevA.106.023301. ieee: G. Bighin, A. Burchianti, F. Minardi, and T. Macrì, “Impurity in a heteronuclear two-component Bose mixture,” Physical Review A, vol. 106, no. 2. American Physical Society, 2022. ista: Bighin G, Burchianti A, Minardi F, Macrì T. 2022. Impurity in a heteronuclear two-component Bose mixture. Physical Review A. 106(2), 023301. mla: Bighin, Giacomo, et al. “Impurity in a Heteronuclear Two-Component Bose Mixture.” Physical Review A, vol. 106, no. 2, 023301, American Physical Society, 2022, doi:10.1103/PhysRevA.106.023301. short: G. Bighin, A. Burchianti, F. Minardi, T. Macrì, Physical Review A 106 (2022). date_created: 2022-08-28T22:02:00Z date_published: 2022-08-04T00:00:00Z date_updated: 2023-08-03T13:20:42Z day: '04' department: - _id: MiLe doi: 10.1103/PhysRevA.106.023301 external_id: arxiv: - '2109.07451' isi: - '000837953600006' intvolume: ' 106' isi: 1 issue: '2' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2109.07451 month: '08' oa: 1 oa_version: Preprint project: - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities publication: Physical Review A publication_identifier: eissn: - 2469-9934 issn: - 2469-9926 publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: Impurity in a heteronuclear two-component Bose mixture type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 106 year: '2022' ... --- _id: '12154' abstract: - lang: eng text: We review our theoretical results of the sound propagation in two-dimensional (2D) systems of ultracold fermionic and bosonic atoms. In the superfluid phase, characterized by the spontaneous symmetry breaking of the U(1) symmetry, there is the coexistence of first and second sound. In the case of weakly-interacting repulsive bosons, we model the recent measurements of the sound velocities of 39K atoms in 2D obtained in the weakly-interacting regime and around the Berezinskii–Kosterlitz–Thouless (BKT) superfluid-to-normal transition temperature. In particular, we perform a quite accurate computation of the superfluid density and show that it is reasonably consistent with the experimental results. For superfluid attractive fermions, we calculate the first and second sound velocities across the whole BCS-BEC crossover. In the low-temperature regime, we reproduce the recent measurements of first-sound speed with 6Li atoms. We also predict that there is mixing between sound modes only in the finite-temperature BEC regime. acknowledgement: "This research is partially supported by University of Padova, BIRD grant “Ultracold atoms\r\nin curved geometries”. KF is supported by Fondazione CARIPARO with a PhD fellowship. AT is\r\npartially supported by French National Research Agency ANR Grant Droplets N. ANR-19-CE30-0003-02. LS thanks Herwig Ott and Sandro Wimberger for their kind invitation to the\r\nInternational Workshop “Quantum Transport with ultracold atoms” (2022)." article_number: '2182' article_processing_charge: Yes article_type: original author: - first_name: Luca full_name: Salasnich, Luca last_name: Salasnich - first_name: Alberto full_name: Cappellaro, Alberto id: 9d13b3cb-30a2-11eb-80dc-f772505e8660 last_name: Cappellaro orcid: 0000-0001-6110-2359 - first_name: Koichiro full_name: Furutani, Koichiro last_name: Furutani - first_name: Andrea full_name: Tononi, Andrea last_name: Tononi - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 citation: ama: Salasnich L, Cappellaro A, Furutani K, Tononi A, Bighin G. First and second sound in two-dimensional bosonic and fermionic superfluids. Symmetry. 2022;14(10). doi:10.3390/sym14102182 apa: Salasnich, L., Cappellaro, A., Furutani, K., Tononi, A., & Bighin, G. (2022). First and second sound in two-dimensional bosonic and fermionic superfluids. Symmetry. MDPI. https://doi.org/10.3390/sym14102182 chicago: Salasnich, Luca, Alberto Cappellaro, Koichiro Furutani, Andrea Tononi, and Giacomo Bighin. “First and Second Sound in Two-Dimensional Bosonic and Fermionic Superfluids.” Symmetry. MDPI, 2022. https://doi.org/10.3390/sym14102182. ieee: L. Salasnich, A. Cappellaro, K. Furutani, A. Tononi, and G. Bighin, “First and second sound in two-dimensional bosonic and fermionic superfluids,” Symmetry, vol. 14, no. 10. MDPI, 2022. ista: Salasnich L, Cappellaro A, Furutani K, Tononi A, Bighin G. 2022. First and second sound in two-dimensional bosonic and fermionic superfluids. Symmetry. 14(10), 2182. mla: Salasnich, Luca, et al. “First and Second Sound in Two-Dimensional Bosonic and Fermionic Superfluids.” Symmetry, vol. 14, no. 10, 2182, MDPI, 2022, doi:10.3390/sym14102182. short: L. Salasnich, A. Cappellaro, K. Furutani, A. Tononi, G. Bighin, Symmetry 14 (2022). date_created: 2023-01-12T12:08:31Z date_published: 2022-10-17T00:00:00Z date_updated: 2023-08-09T10:13:17Z day: '17' ddc: - '530' department: - _id: MiLe doi: 10.3390/sym14102182 external_id: isi: - '000875039200001' file: - access_level: open_access checksum: 9b6bd0e484834dd76d7b26e3c5fba8bd content_type: application/pdf creator: dernst date_created: 2023-01-24T10:56:12Z date_updated: 2023-01-24T10:56:12Z file_id: '12361' file_name: 2022_Symmetry_Salsnich.pdf file_size: 843723 relation: main_file success: 1 file_date_updated: 2023-01-24T10:56:12Z has_accepted_license: '1' intvolume: ' 14' isi: 1 issue: '10' keyword: - Physics and Astronomy (miscellaneous) - General Mathematics - Chemistry (miscellaneous) - Computer Science (miscellaneous) language: - iso: eng month: '10' oa: 1 oa_version: Published Version publication: Symmetry publication_identifier: issn: - 2073-8994 publication_status: published publisher: MDPI quality_controlled: '1' scopus_import: '1' status: public title: First and second sound in two-dimensional bosonic and fermionic superfluids tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87 volume: 14 year: '2022' ... --- _id: '9606' abstract: - lang: eng text: Sound propagation is a macroscopic manifestation of the interplay between the equilibrium thermodynamics and the dynamical transport properties of fluids. Here, for a two-dimensional system of ultracold fermions, we calculate the first and second sound velocities across the whole BCS-BEC crossover, and we analyze the system response to an external perturbation. In the low-temperature regime we reproduce the recent measurements [Phys. Rev. Lett. 124, 240403 (2020)] of the first sound velocity, which, due to the decoupling of density and entropy fluctuations, is the sole mode excited by a density probe. Conversely, a heat perturbation excites only the second sound, which, being sensitive to the superfluid depletion, vanishes in the deep BCS regime and jumps discontinuously to zero at the Berezinskii-Kosterlitz-Thouless superfluid transition. A mixing between the modes occurs only in the finite-temperature BEC regime, where our theory converges to the purely bosonic results. acknowledgement: "G.B. acknowledges support from the Austrian Science Fund (FWF), under Project No. M2641-N27. This work was\r\npartially supported by the University of Padua, BIRD project “Superfluid properties of Fermi gases in optical potentials.”\r\nThe authors thank Miki Ota, Tomoki Ozawa, Sandro Stringari, Tilman Enss, Hauke Biss, Henning Moritz, and Nicolò Defenu for fruitful discussions. The authors thank Henning Moritz and Markus Bohlen for providing their experimental\r\ndata." article_number: L061303 article_processing_charge: No article_type: letter_note author: - first_name: A. full_name: Tononi, A. last_name: Tononi - first_name: Alberto full_name: Cappellaro, Alberto id: 9d13b3cb-30a2-11eb-80dc-f772505e8660 last_name: Cappellaro orcid: 0000-0001-6110-2359 - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: L. full_name: Salasnich, L. last_name: Salasnich citation: ama: Tononi A, Cappellaro A, Bighin G, Salasnich L. Propagation of first and second sound in a two-dimensional Fermi superfluid. Physical Review A. 2021;103(6). doi:10.1103/PhysRevA.103.L061303 apa: Tononi, A., Cappellaro, A., Bighin, G., & Salasnich, L. (2021). Propagation of first and second sound in a two-dimensional Fermi superfluid. Physical Review A. American Physical Society. https://doi.org/10.1103/PhysRevA.103.L061303 chicago: Tononi, A., Alberto Cappellaro, Giacomo Bighin, and L. Salasnich. “Propagation of First and Second Sound in a Two-Dimensional Fermi Superfluid.” Physical Review A. American Physical Society, 2021. https://doi.org/10.1103/PhysRevA.103.L061303. ieee: A. Tononi, A. Cappellaro, G. Bighin, and L. Salasnich, “Propagation of first and second sound in a two-dimensional Fermi superfluid,” Physical Review A, vol. 103, no. 6. American Physical Society, 2021. ista: Tononi A, Cappellaro A, Bighin G, Salasnich L. 2021. Propagation of first and second sound in a two-dimensional Fermi superfluid. Physical Review A. 103(6), L061303. mla: Tononi, A., et al. “Propagation of First and Second Sound in a Two-Dimensional Fermi Superfluid.” Physical Review A, vol. 103, no. 6, L061303, American Physical Society, 2021, doi:10.1103/PhysRevA.103.L061303. short: A. Tononi, A. Cappellaro, G. Bighin, L. Salasnich, Physical Review A 103 (2021). date_created: 2021-06-27T22:01:49Z date_published: 2021-06-01T00:00:00Z date_updated: 2023-08-10T13:37:25Z day: '01' department: - _id: MiLe doi: 10.1103/PhysRevA.103.L061303 external_id: arxiv: - '2009.06491' isi: - '000662296700014' intvolume: ' 103' isi: 1 issue: '6' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/2009.06491 month: '06' oa: 1 oa_version: Preprint publication: Physical Review A publication_identifier: eissn: - '24699934' issn: - '24699926' publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: Propagation of first and second sound in a two-dimensional Fermi superfluid type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 103 year: '2021' ... --- _id: '10631' abstract: - lang: eng text: We combine experimental and theoretical approaches to explore excited rotational states of molecules embedded in helium nanodroplets using CS2 and I2 as examples. Laser-induced nonadiabatic molecular alignment is employed to measure spectral lines for rotational states extending beyond those initially populated at the 0.37 K droplet temperature. We construct a simple quantum-mechanical model, based on a linear rotor coupled to a single-mode bosonic bath, to determine the rotational energy structure in its entirety. The calculated and measured spectral lines are in good agreement. We show that the effect of the surrounding superfluid on molecular rotation can be rationalized by a single quantity, the angular momentum, transferred from the molecule to the droplet. acknowledgement: I.C. acknowledges the support by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 665385. G.B. acknowledges support from the Austrian Science Fund (FWF), under project No. M2461-N27. M.L. acknowledges support by the Austrian Science Fund (FWF), under project No. P29902-N27, and by the European Research Council (ERC) Starting Grant No. 801770 (ANGULON). H.S acknowledges support from the European Research Council-AdG (Project No. 320459, DropletControl) and from The Villum Foundation through a Villum Investigator grant no. 25886. article_number: L061303 article_processing_charge: No article_type: original author: - first_name: Igor full_name: Cherepanov, Igor id: 339C7E5A-F248-11E8-B48F-1D18A9856A87 last_name: Cherepanov - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Constant A. full_name: Schouder, Constant A. last_name: Schouder - first_name: Adam S. full_name: Chatterley, Adam S. last_name: Chatterley - first_name: Simon H. full_name: Albrechtsen, Simon H. last_name: Albrechtsen - first_name: Alberto Viñas full_name: Muñoz, Alberto Viñas last_name: Muñoz - first_name: Lars full_name: Christiansen, Lars last_name: Christiansen - first_name: Henrik full_name: Stapelfeldt, Henrik last_name: Stapelfeldt - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 citation: ama: Cherepanov I, Bighin G, Schouder CA, et al. Excited rotational states of molecules in a superfluid. Physical Review A. 2021;104(6). doi:10.1103/PhysRevA.104.L061303 apa: Cherepanov, I., Bighin, G., Schouder, C. A., Chatterley, A. S., Albrechtsen, S. H., Muñoz, A. V., … Lemeshko, M. (2021). Excited rotational states of molecules in a superfluid. Physical Review A. American Physical Society. https://doi.org/10.1103/PhysRevA.104.L061303 chicago: Cherepanov, Igor, Giacomo Bighin, Constant A. Schouder, Adam S. Chatterley, Simon H. Albrechtsen, Alberto Viñas Muñoz, Lars Christiansen, Henrik Stapelfeldt, and Mikhail Lemeshko. “Excited Rotational States of Molecules in a Superfluid.” Physical Review A. American Physical Society, 2021. https://doi.org/10.1103/PhysRevA.104.L061303. ieee: I. Cherepanov et al., “Excited rotational states of molecules in a superfluid,” Physical Review A, vol. 104, no. 6. American Physical Society, 2021. ista: Cherepanov I, Bighin G, Schouder CA, Chatterley AS, Albrechtsen SH, Muñoz AV, Christiansen L, Stapelfeldt H, Lemeshko M. 2021. Excited rotational states of molecules in a superfluid. Physical Review A. 104(6), L061303. mla: Cherepanov, Igor, et al. “Excited Rotational States of Molecules in a Superfluid.” Physical Review A, vol. 104, no. 6, L061303, American Physical Society, 2021, doi:10.1103/PhysRevA.104.L061303. short: I. Cherepanov, G. Bighin, C.A. Schouder, A.S. Chatterley, S.H. Albrechtsen, A.V. Muñoz, L. Christiansen, H. Stapelfeldt, M. Lemeshko, Physical Review A 104 (2021). date_created: 2022-01-16T23:01:29Z date_published: 2021-12-30T00:00:00Z date_updated: 2023-08-17T06:52:17Z day: '30' department: - _id: MiLe doi: 10.1103/PhysRevA.104.L061303 ec_funded: 1 external_id: arxiv: - '2107.00468' isi: - '000739618300001' intvolume: ' 104' isi: 1 issue: '6' language: - iso: eng main_file_link: - open_access: '1' url: http://128.84.4.18/abs/2107.00468 month: '12' oa: 1 oa_version: Preprint project: - _id: 26031614-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P29902 name: Quantum rotations in the presence of a many-body environment - _id: 2688CF98-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '801770' name: 'Angulon: physics and applications of a new quasiparticle' - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities publication: Physical Review A publication_identifier: eissn: - 2469-9934 issn: - 2469-9926 publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: Excited rotational states of molecules in a superfluid type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 104 year: '2021' ... --- _id: '8170' abstract: - lang: eng text: "Alignment of OCS, CS2, and I2 molecules embedded in helium nanodroplets is measured as a function\r\nof time following rotational excitation by a nonresonant, comparatively weak ps laser pulse. The distinct\r\npeaks in the power spectra, obtained by Fourier analysis, are used to determine the rotational, B, and\r\ncentrifugal distortion, D, constants. For OCS, B and D match the values known from IR spectroscopy. For\r\nCS2 and I2, they are the first experimental results reported. The alignment dynamics calculated from the\r\ngas-phase rotational Schrödinger equation, using the experimental in-droplet B and D values, agree in\r\ndetail with the measurement for all three molecules. The rotational spectroscopy technique for molecules in\r\nhelium droplets introduced here should apply to a range of molecules and complexes." acknowledgement: "H. S. acknowledges support from the European Research Council-AdG (Project No. 320459, DropletControl)\r\nand from The Villum Foundation through a Villum Investigator Grant No. 25886. M. L. acknowledges support\r\nby the Austrian Science Fund (FWF), under Project No. P29902-N27, and by the European Research Council\r\n(ERC) Starting Grant No. 801770 (ANGULON). G. B. acknowledges support from the Austrian Science Fund\r\n(FWF), under Project No. M2641-N27. I. C. acknowledges support by the European Union’s Horizon 2020 research and\r\ninnovation programme under the Marie Skłodowska-Curie Grant Agreement No. 665385. Computational resources for\r\nthe PIMC simulations were provided by the division for scientific computing at the Johannes Kepler University." article_number: '013001' article_processing_charge: No article_type: original author: - first_name: Adam S. full_name: Chatterley, Adam S. last_name: Chatterley - first_name: Lars full_name: Christiansen, Lars last_name: Christiansen - first_name: Constant A. full_name: Schouder, Constant A. last_name: Schouder - first_name: Anders V. full_name: Jørgensen, Anders V. last_name: Jørgensen - first_name: Benjamin full_name: Shepperson, Benjamin last_name: Shepperson - first_name: Igor full_name: Cherepanov, Igor id: 339C7E5A-F248-11E8-B48F-1D18A9856A87 last_name: Cherepanov - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Robert E. full_name: Zillich, Robert E. last_name: Zillich - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 - first_name: Henrik full_name: Stapelfeldt, Henrik last_name: Stapelfeldt citation: ama: 'Chatterley AS, Christiansen L, Schouder CA, et al. Rotational coherence spectroscopy of molecules in Helium nanodroplets: Reconciling the time and the frequency domains. Physical Review Letters. 2020;125(1). doi:10.1103/PhysRevLett.125.013001' apa: 'Chatterley, A. S., Christiansen, L., Schouder, C. A., Jørgensen, A. V., Shepperson, B., Cherepanov, I., … Stapelfeldt, H. (2020). Rotational coherence spectroscopy of molecules in Helium nanodroplets: Reconciling the time and the frequency domains. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.125.013001' chicago: 'Chatterley, Adam S., Lars Christiansen, Constant A. Schouder, Anders V. Jørgensen, Benjamin Shepperson, Igor Cherepanov, Giacomo Bighin, Robert E. Zillich, Mikhail Lemeshko, and Henrik Stapelfeldt. “Rotational Coherence Spectroscopy of Molecules in Helium Nanodroplets: Reconciling the Time and the Frequency Domains.” Physical Review Letters. American Physical Society, 2020. https://doi.org/10.1103/PhysRevLett.125.013001.' ieee: 'A. S. Chatterley et al., “Rotational coherence spectroscopy of molecules in Helium nanodroplets: Reconciling the time and the frequency domains,” Physical Review Letters, vol. 125, no. 1. American Physical Society, 2020.' ista: 'Chatterley AS, Christiansen L, Schouder CA, Jørgensen AV, Shepperson B, Cherepanov I, Bighin G, Zillich RE, Lemeshko M, Stapelfeldt H. 2020. Rotational coherence spectroscopy of molecules in Helium nanodroplets: Reconciling the time and the frequency domains. Physical Review Letters. 125(1), 013001.' mla: 'Chatterley, Adam S., et al. “Rotational Coherence Spectroscopy of Molecules in Helium Nanodroplets: Reconciling the Time and the Frequency Domains.” Physical Review Letters, vol. 125, no. 1, 013001, American Physical Society, 2020, doi:10.1103/PhysRevLett.125.013001.' short: A.S. Chatterley, L. Christiansen, C.A. Schouder, A.V. Jørgensen, B. Shepperson, I. Cherepanov, G. Bighin, R.E. Zillich, M. Lemeshko, H. Stapelfeldt, Physical Review Letters 125 (2020). date_created: 2020-07-26T22:01:02Z date_published: 2020-07-03T00:00:00Z date_updated: 2023-08-22T08:22:43Z day: '03' department: - _id: MiLe doi: 10.1103/PhysRevLett.125.013001 ec_funded: 1 external_id: arxiv: - '2006.02694' isi: - '000544526900006' intvolume: ' 125' isi: 1 issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/2006.02694 month: '07' oa: 1 oa_version: Preprint project: - _id: 26031614-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P29902 name: Quantum rotations in the presence of a many-body environment - _id: 2688CF98-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '801770' name: 'Angulon: physics and applications of a new quasiparticle' - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program publication: Physical Review Letters publication_identifier: eissn: - '10797114' issn: - '00319007' publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: 'Rotational coherence spectroscopy of molecules in Helium nanodroplets: Reconciling the time and the frequency domains' type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 125 year: '2020' ... --- _id: '8587' abstract: - lang: eng text: Inspired by the possibility to experimentally manipulate and enhance chemical reactivity in helium nanodroplets, we investigate the effective interaction and the resulting correlations between two diatomic molecules immersed in a bath of bosons. By analogy with the bipolaron, we introduce the biangulon quasiparticle describing two rotating molecules that align with respect to each other due to the effective attractive interaction mediated by the excitations of the bath. We study this system in different parameter regimes and apply several theoretical approaches to describe its properties. Using a Born–Oppenheimer approximation, we investigate the dependence of the effective intermolecular interaction on the rotational state of the two molecules. In the strong-coupling regime, a product-state ansatz shows that the molecules tend to have a strong alignment in the ground state. To investigate the system in the weak-coupling regime, we apply a one-phonon excitation variational ansatz, which allows us to access the energy spectrum. In comparison to the angulon quasiparticle, the biangulon shows shifted angulon instabilities and an additional spectral instability, where resonant angular momentum transfer between the molecules and the bath takes place. These features are proposed as an experimentally observable signature for the formation of the biangulon quasiparticle. Finally, by using products of single angulon and bare impurity wave functions as basis states, we introduce a diagonalization scheme that allows us to describe the transition from two separated angulons to a biangulon as a function of the distance between the two molecules. acknowledgement: We are grateful to Areg Ghazaryan for valuable discussions. M.L. acknowledges support from the Austrian Science Fund (FWF) under Project No. P29902-N27 and from the European Research Council (ERC) Starting Grant No. 801770 (ANGULON). G.B. acknowledges support from the Austrian Science Fund (FWF) under Project No. M2461-N27. A.D. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the European Research Council (ERC) Grant Agreement No. 694227 and under the Marie Sklodowska-Curie Grant Agreement No. 836146. R.S. was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC-2111 – 390814868. article_number: '164302' article_processing_charge: No article_type: original author: - first_name: Xiang full_name: Li, Xiang id: 4B7E523C-F248-11E8-B48F-1D18A9856A87 last_name: Li - first_name: Enderalp full_name: Yakaboylu, Enderalp id: 38CB71F6-F248-11E8-B48F-1D18A9856A87 last_name: Yakaboylu orcid: 0000-0001-5973-0874 - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Richard full_name: Schmidt, Richard last_name: Schmidt - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 - first_name: Andreas full_name: Deuchert, Andreas id: 4DA65CD0-F248-11E8-B48F-1D18A9856A87 last_name: Deuchert orcid: 0000-0003-3146-6746 citation: ama: Li X, Yakaboylu E, Bighin G, Schmidt R, Lemeshko M, Deuchert A. Intermolecular forces and correlations mediated by a phonon bath. The Journal of Chemical Physics. 2020;152(16). doi:10.1063/1.5144759 apa: Li, X., Yakaboylu, E., Bighin, G., Schmidt, R., Lemeshko, M., & Deuchert, A. (2020). Intermolecular forces and correlations mediated by a phonon bath. The Journal of Chemical Physics. AIP Publishing. https://doi.org/10.1063/1.5144759 chicago: Li, Xiang, Enderalp Yakaboylu, Giacomo Bighin, Richard Schmidt, Mikhail Lemeshko, and Andreas Deuchert. “Intermolecular Forces and Correlations Mediated by a Phonon Bath.” The Journal of Chemical Physics. AIP Publishing, 2020. https://doi.org/10.1063/1.5144759. ieee: X. Li, E. Yakaboylu, G. Bighin, R. Schmidt, M. Lemeshko, and A. Deuchert, “Intermolecular forces and correlations mediated by a phonon bath,” The Journal of Chemical Physics, vol. 152, no. 16. AIP Publishing, 2020. ista: Li X, Yakaboylu E, Bighin G, Schmidt R, Lemeshko M, Deuchert A. 2020. Intermolecular forces and correlations mediated by a phonon bath. The Journal of Chemical Physics. 152(16), 164302. mla: Li, Xiang, et al. “Intermolecular Forces and Correlations Mediated by a Phonon Bath.” The Journal of Chemical Physics, vol. 152, no. 16, 164302, AIP Publishing, 2020, doi:10.1063/1.5144759. short: X. Li, E. Yakaboylu, G. Bighin, R. Schmidt, M. Lemeshko, A. Deuchert, The Journal of Chemical Physics 152 (2020). date_created: 2020-09-30T10:33:17Z date_published: 2020-04-27T00:00:00Z date_updated: 2023-09-07T13:16:42Z day: '27' department: - _id: MiLe - _id: RoSe doi: 10.1063/1.5144759 ec_funded: 1 external_id: arxiv: - '1912.02658' isi: - '000530448300001' intvolume: ' 152' isi: 1 issue: '16' keyword: - Physical and Theoretical Chemistry - General Physics and Astronomy language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1912.02658 month: '04' oa: 1 oa_version: Preprint project: - _id: 26031614-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P29902 name: Quantum rotations in the presence of a many-body environment - _id: 2688CF98-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '801770' name: 'Angulon: physics and applications of a new quasiparticle' - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities - _id: 25C6DC12-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '694227' name: Analysis of quantum many-body systems publication: The Journal of Chemical Physics publication_identifier: eissn: - 1089-7690 issn: - 0021-9606 publication_status: published publisher: AIP Publishing quality_controlled: '1' related_material: record: - id: '8958' relation: dissertation_contains status: public status: public title: Intermolecular forces and correlations mediated by a phonon bath type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 152 year: '2020' ... --- _id: '8644' abstract: - lang: eng text: Determining the phase diagram of systems consisting of smaller subsystems 'connected' via a tunable coupling is a challenging task relevant for a variety of physical settings. A general question is whether new phases, not present in the uncoupled limit, may arise. We use machine learning and a suitable quasidistance between different points of the phase diagram to study layered spin models, in which the spin variables constituting each of the uncoupled systems (to which we refer as layers) are coupled to each other via an interlayer coupling. In such systems, in general, composite order parameters involving spins of different layers may emerge as a consequence of the interlayer coupling. We focus on the layered Ising and Ashkin–Teller models as a paradigmatic case study, determining their phase diagram via the application of a machine learning algorithm to the Monte Carlo data. Remarkably our technique is able to correctly characterize all the system phases also in the case of hidden order parameters, i.e. order parameters whose expression in terms of the microscopic configurations would require additional preprocessing of the data fed to the algorithm. We correctly retrieve the three known phases of the Ashkin–Teller model with ferromagnetic couplings, including the phase described by a composite order parameter. For the bilayer and trilayer Ising models the phases we find are only the ferromagnetic and the paramagnetic ones. Within the approach we introduce, owing to the construction of convolutional neural networks, naturally suitable for layered image-like data with arbitrary number of layers, no preprocessing of the Monte Carlo data is needed, also with regard to its spatial structure. The physical meaning of our results is discussed and compared with analytical data, where available. Yet, the method can be used without any a priori knowledge of the phases one seeks to find and can be applied to other models and structures. acknowledgement: We thank Gesualdo Delfino, Michele Fabrizio, Piero Ferrarese, Robert Konik, Christoph Lampert and Mikhail Lemeshko for stimulating discussions at various stages of this work. WR has received funding from the EU Horizon 2020 program under the Marie Skłodowska-Curie Grant Agreement No. 665385 and is a recipient of a DOC Fellowship of the Austrian Academy of Sciences. GB acknowledges support from the Austrian Science Fund (FWF), under project No. M2641-N27. ND acknowledges support by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) via Collaborative Research Center SFB 1225 (ISOQUANT)--project-id 273811115--and under Germany's Excellence Strategy 'EXC-2181/1-390900948' (the Heidelberg STRUCTURES Excellence Cluster). article_number: '093026' article_processing_charge: No article_type: original author: - first_name: Wojciech full_name: Rzadkowski, Wojciech id: 48C55298-F248-11E8-B48F-1D18A9856A87 last_name: Rzadkowski orcid: 0000-0002-1106-4419 - first_name: N full_name: Defenu, N last_name: Defenu - first_name: S full_name: Chiacchiera, S last_name: Chiacchiera - first_name: A full_name: Trombettoni, A last_name: Trombettoni - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 citation: ama: Rzadkowski W, Defenu N, Chiacchiera S, Trombettoni A, Bighin G. Detecting composite orders in layered models via machine learning. New Journal of Physics. 2020;22(9). doi:10.1088/1367-2630/abae44 apa: Rzadkowski, W., Defenu, N., Chiacchiera, S., Trombettoni, A., & Bighin, G. (2020). Detecting composite orders in layered models via machine learning. New Journal of Physics. IOP Publishing. https://doi.org/10.1088/1367-2630/abae44 chicago: Rzadkowski, Wojciech, N Defenu, S Chiacchiera, A Trombettoni, and Giacomo Bighin. “Detecting Composite Orders in Layered Models via Machine Learning.” New Journal of Physics. IOP Publishing, 2020. https://doi.org/10.1088/1367-2630/abae44. ieee: W. Rzadkowski, N. Defenu, S. Chiacchiera, A. Trombettoni, and G. Bighin, “Detecting composite orders in layered models via machine learning,” New Journal of Physics, vol. 22, no. 9. IOP Publishing, 2020. ista: Rzadkowski W, Defenu N, Chiacchiera S, Trombettoni A, Bighin G. 2020. Detecting composite orders in layered models via machine learning. New Journal of Physics. 22(9), 093026. mla: Rzadkowski, Wojciech, et al. “Detecting Composite Orders in Layered Models via Machine Learning.” New Journal of Physics, vol. 22, no. 9, 093026, IOP Publishing, 2020, doi:10.1088/1367-2630/abae44. short: W. Rzadkowski, N. Defenu, S. Chiacchiera, A. Trombettoni, G. Bighin, New Journal of Physics 22 (2020). date_created: 2020-10-11T22:01:14Z date_published: 2020-09-01T00:00:00Z date_updated: 2023-09-07T13:44:16Z day: '01' ddc: - '530' department: - _id: MiLe doi: 10.1088/1367-2630/abae44 ec_funded: 1 external_id: isi: - '000573298000001' file: - access_level: open_access checksum: c9238fff422e7a957c3a0d559f756b3a content_type: application/pdf creator: dernst date_created: 2020-10-12T12:18:47Z date_updated: 2020-10-12T12:18:47Z file_id: '8650' file_name: 2020_NewJournalPhysics_Rzdkowski.pdf file_size: 2725143 relation: main_file success: 1 file_date_updated: 2020-10-12T12:18:47Z has_accepted_license: '1' intvolume: ' 22' isi: 1 issue: '9' language: - iso: eng month: '09' oa: 1 oa_version: Published Version project: - _id: 2564DBCA-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '665385' name: International IST Doctoral Program - _id: 05A235A0-7A3F-11EA-A408-12923DDC885E grant_number: '25681' name: Analytic and machine learning approaches to composite quantum impurities - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities publication: New Journal of Physics publication_identifier: issn: - '13672630' publication_status: published publisher: IOP Publishing quality_controlled: '1' related_material: record: - id: '10759' relation: dissertation_contains status: public scopus_import: '1' status: public title: Detecting composite orders in layered models via machine learning tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 22 year: '2020' ... --- _id: '6940' abstract: - lang: eng text: "We study the effect of a linear tunneling coupling between two-dimensional systems, each separately\r\nexhibiting the topological Berezinskii-Kosterlitz-Thouless (BKT) transition. In the uncoupled limit, there\r\nare two phases: one where the one-body correlation functions are algebraically decaying and the other with\r\nexponential decay. When the linear coupling is turned on, a third BKT-paired phase emerges, in which one-body correlations are exponentially decaying, while two-body correlation functions exhibit power-law\r\ndecay. We perform numerical simulations in the paradigmatic case of two coupled XY models at finite\r\ntemperature, finding evidences that for any finite value of the interlayer coupling, the BKT-paired phase is\r\npresent. We provide a picture of the phase diagram using a renormalization group approach." acknowledgement: "We thank S. Chiacchiera, G. Delfino, N. Dupuis, T. Enss, M. Fabrizio and G. Gori for many stimulating discussions.\r\nG.B. acknowledges support from the Austrian Science Fund (FWF), under project No. M2461-N27. N.D. acknowledges\r\nsupport from Deutsche Forschungsgemeinschaft (DFG) under Germany’s Excellence Strategy EXC-2181/1 - 390900948 (the Heidelberg STRUCTURES Excellence Cluster) and from the DFG Collaborative Research Centre “SFB 1225 ISOQUANT”. Support from the CNR/MTA Italy-Hungary 2019-2021 Joint Project “Strongly interacting systems in confined geometries” is gratefully acknowledged." article_number: '100601' article_processing_charge: No article_type: original author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Nicolò full_name: Defenu, Nicolò last_name: Defenu - first_name: István full_name: Nándori, István last_name: Nándori - first_name: Luca full_name: Salasnich, Luca last_name: Salasnich - first_name: Andrea full_name: Trombettoni, Andrea last_name: Trombettoni citation: ama: Bighin G, Defenu N, Nándori I, Salasnich L, Trombettoni A. Berezinskii-Kosterlitz-Thouless paired phase in coupled XY models. Physical Review Letters. 2019;123(10). doi:10.1103/physrevlett.123.100601 apa: Bighin, G., Defenu, N., Nándori, I., Salasnich, L., & Trombettoni, A. (2019). Berezinskii-Kosterlitz-Thouless paired phase in coupled XY models. Physical Review Letters. American Physical Society. https://doi.org/10.1103/physrevlett.123.100601 chicago: Bighin, Giacomo, Nicolò Defenu, István Nándori, Luca Salasnich, and Andrea Trombettoni. “Berezinskii-Kosterlitz-Thouless Paired Phase in Coupled XY Models.” Physical Review Letters. American Physical Society, 2019. https://doi.org/10.1103/physrevlett.123.100601. ieee: G. Bighin, N. Defenu, I. Nándori, L. Salasnich, and A. Trombettoni, “Berezinskii-Kosterlitz-Thouless paired phase in coupled XY models,” Physical Review Letters, vol. 123, no. 10. American Physical Society, 2019. ista: Bighin G, Defenu N, Nándori I, Salasnich L, Trombettoni A. 2019. Berezinskii-Kosterlitz-Thouless paired phase in coupled XY models. Physical Review Letters. 123(10), 100601. mla: Bighin, Giacomo, et al. “Berezinskii-Kosterlitz-Thouless Paired Phase in Coupled XY Models.” Physical Review Letters, vol. 123, no. 10, 100601, American Physical Society, 2019, doi:10.1103/physrevlett.123.100601. short: G. Bighin, N. Defenu, I. Nándori, L. Salasnich, A. Trombettoni, Physical Review Letters 123 (2019). date_created: 2019-10-14T06:31:13Z date_published: 2019-09-06T00:00:00Z date_updated: 2023-08-30T06:57:53Z day: '06' department: - _id: MiLe doi: 10.1103/physrevlett.123.100601 external_id: arxiv: - '1907.06253' isi: - '000483587200004' intvolume: ' 123' isi: 1 issue: '10' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1907.06253 month: '09' oa: 1 oa_version: Preprint project: - _id: 26986C82-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: M02641 name: A path-integral approach to composite impurities publication: Physical Review Letters publication_identifier: eissn: - 1079-7114 issn: - 0031-9007 publication_status: published publisher: American Physical Society quality_controlled: '1' related_material: link: - description: News auf IST Website relation: press_release url: https://ist.ac.at/en/news/new-form-of-magnetism-found/ scopus_import: '1' status: public title: Berezinskii-Kosterlitz-Thouless paired phase in coupled XY models type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 123 year: '2019' ... --- _id: '5886' abstract: - lang: eng text: Problems involving quantum impurities, in which one or a few particles are interacting with a macroscopic environment, represent a pervasive paradigm, spanning across atomic, molecular, and condensed-matter physics. In this paper we introduce new variational approaches to quantum impurities and apply them to the Fröhlich polaron–a quasiparticle formed out of an electron (or other point-like impurity) in a polar medium, and to the angulon–a quasiparticle formed out of a rotating molecule in a bosonic bath. We benchmark these approaches against established theories, evaluating their accuracy as a function of the impurity-bath coupling. article_processing_charge: No author: - first_name: Xiang full_name: Li, Xiang id: 4B7E523C-F248-11E8-B48F-1D18A9856A87 last_name: Li - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Enderalp full_name: Yakaboylu, Enderalp id: 38CB71F6-F248-11E8-B48F-1D18A9856A87 last_name: Yakaboylu orcid: 0000-0001-5973-0874 - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 citation: ama: 'Li X, Bighin G, Yakaboylu E, Lemeshko M. Variational approaches to quantum impurities: from the Fröhlich polaron to the angulon. Molecular Physics. 2019. doi:10.1080/00268976.2019.1567852' apa: 'Li, X., Bighin, G., Yakaboylu, E., & Lemeshko, M. (2019). Variational approaches to quantum impurities: from the Fröhlich polaron to the angulon. Molecular Physics. Taylor and Francis. https://doi.org/10.1080/00268976.2019.1567852' chicago: 'Li, Xiang, Giacomo Bighin, Enderalp Yakaboylu, and Mikhail Lemeshko. “Variational Approaches to Quantum Impurities: From the Fröhlich Polaron to the Angulon.” Molecular Physics. Taylor and Francis, 2019. https://doi.org/10.1080/00268976.2019.1567852.' ieee: 'X. Li, G. Bighin, E. Yakaboylu, and M. Lemeshko, “Variational approaches to quantum impurities: from the Fröhlich polaron to the angulon,” Molecular Physics. Taylor and Francis, 2019.' ista: 'Li X, Bighin G, Yakaboylu E, Lemeshko M. 2019. Variational approaches to quantum impurities: from the Fröhlich polaron to the angulon. Molecular Physics.' mla: 'Li, Xiang, et al. “Variational Approaches to Quantum Impurities: From the Fröhlich Polaron to the Angulon.” Molecular Physics, Taylor and Francis, 2019, doi:10.1080/00268976.2019.1567852.' short: X. Li, G. Bighin, E. Yakaboylu, M. Lemeshko, Molecular Physics (2019). date_created: 2019-01-27T22:59:10Z date_published: 2019-01-18T00:00:00Z date_updated: 2023-09-07T13:16:42Z day: '18' ddc: - '530' department: - _id: MiLe doi: 10.1080/00268976.2019.1567852 ec_funded: 1 external_id: isi: - '000474641400008' file: - access_level: open_access checksum: 178964744b636a6f036372f4f090a657 content_type: application/pdf creator: dernst date_created: 2019-01-29T08:32:57Z date_updated: 2020-07-14T12:47:13Z file_id: '5896' file_name: 2019_MolecularPhysics_Li.pdf file_size: 1309966 relation: main_file file_date_updated: 2020-07-14T12:47:13Z has_accepted_license: '1' isi: 1 language: - iso: eng month: '01' oa: 1 oa_version: Published Version project: - _id: 26031614-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P29902 name: Quantum rotations in the presence of a many-body environment - _id: 25681D80-B435-11E9-9278-68D0E5697425 call_identifier: FP7 grant_number: '291734' name: International IST Postdoc Fellowship Programme publication: Molecular Physics publication_identifier: issn: - '00268976' publication_status: published publisher: Taylor and Francis quality_controlled: '1' related_material: record: - id: '8958' relation: dissertation_contains status: public scopus_import: '1' status: public title: 'Variational approaches to quantum impurities: from the Fröhlich polaron to the angulon' tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 year: '2019' ... --- _id: '420' abstract: - lang: eng text: We analyze the theoretical derivation of the beyond-mean-field equation of state for two-dimensional gas of dilute, ultracold alkali-metal atoms in the Bardeen–Cooper–Schrieffer (BCS) to Bose–Einstein condensate (BEC) crossover. We show that at zero temperature our theory — considering Gaussian fluctuations on top of the mean-field equation of state — is in very good agreement with experimental data. Subsequently, we investigate the superfluid density at finite temperature and its renormalization due to the proliferation of vortex–antivortex pairs. By doing so, we determine the Berezinskii–Kosterlitz–Thouless (BKT) critical temperature — at which the renormalized superfluid density jumps to zero — as a function of the inter-atomic potential strength. We find that the Nelson–Kosterlitz criterion overestimates the BKT temperature with respect to the renormalization group equations, this effect being particularly relevant in the intermediate regime of the crossover. article_processing_charge: No author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Luca full_name: Salasnich, Luca last_name: Salasnich citation: ama: Bighin G, Salasnich L. Renormalization of the superfluid density in the two-dimensional BCS-BEC crossover. International Journal of Modern Physics B. 2018;32(17):1840022. doi:10.1142/S0217979218400222 apa: Bighin, G., & Salasnich, L. (2018). Renormalization of the superfluid density in the two-dimensional BCS-BEC crossover. International Journal of Modern Physics B. World Scientific Publishing. https://doi.org/10.1142/S0217979218400222 chicago: Bighin, Giacomo, and Luca Salasnich. “Renormalization of the Superfluid Density in the Two-Dimensional BCS-BEC Crossover.” International Journal of Modern Physics B. World Scientific Publishing, 2018. https://doi.org/10.1142/S0217979218400222. ieee: G. Bighin and L. Salasnich, “Renormalization of the superfluid density in the two-dimensional BCS-BEC crossover,” International Journal of Modern Physics B, vol. 32, no. 17. World Scientific Publishing, p. 1840022, 2018. ista: Bighin G, Salasnich L. 2018. Renormalization of the superfluid density in the two-dimensional BCS-BEC crossover. International Journal of Modern Physics B. 32(17), 1840022. mla: Bighin, Giacomo, and Luca Salasnich. “Renormalization of the Superfluid Density in the Two-Dimensional BCS-BEC Crossover.” International Journal of Modern Physics B, vol. 32, no. 17, World Scientific Publishing, 2018, p. 1840022, doi:10.1142/S0217979218400222. short: G. Bighin, L. Salasnich, International Journal of Modern Physics B 32 (2018) 1840022. date_created: 2018-12-11T11:46:22Z date_published: 2018-07-10T00:00:00Z date_updated: 2023-09-18T08:09:59Z day: '10' department: - _id: MiLe doi: 10.1142/S0217979218400222 external_id: isi: - '000438217300007' intvolume: ' 32' isi: 1 issue: '17' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1710.11171 month: '07' oa: 1 oa_version: Preprint page: '1840022' publication: International Journal of Modern Physics B publication_status: published publisher: World Scientific Publishing publist_id: '7402' quality_controlled: '1' scopus_import: '1' status: public title: Renormalization of the superfluid density in the two-dimensional BCS-BEC crossover type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 32 year: '2018' ... --- _id: '6339' abstract: - lang: eng text: We introduce a diagrammatic Monte Carlo approach to angular momentum properties of quantum many-particle systems possessing a macroscopic number of degrees of freedom. The treatment is based on a diagrammatic expansion that merges the usual Feynman diagrams with the angular momentum diagrams known from atomic and nuclear structure theory, thereby incorporating the non-Abelian algebra inherent to quantum rotations. Our approach is applicable at arbitrary coupling, is free of systematic errors and of finite-size effects, and naturally provides access to the impurity Green function. We exemplify the technique by obtaining an all-coupling solution of the angulon model; however, the method is quite general and can be applied to a broad variety of systems in which particles exchange quantum angular momentum with their many-body environment. article_number: '165301' article_processing_charge: No author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Timur full_name: Tscherbul, Timur last_name: Tscherbul - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 citation: ama: Bighin G, Tscherbul T, Lemeshko M. Diagrammatic Monte Carlo approach to angular momentum in quantum many-particle systems. Physical Review Letters. 2018;121(16). doi:10.1103/physrevlett.121.165301 apa: Bighin, G., Tscherbul, T., & Lemeshko, M. (2018). Diagrammatic Monte Carlo approach to angular momentum in quantum many-particle systems. Physical Review Letters. American Physical Society. https://doi.org/10.1103/physrevlett.121.165301 chicago: Bighin, Giacomo, Timur Tscherbul, and Mikhail Lemeshko. “Diagrammatic Monte Carlo Approach to Angular Momentum in Quantum Many-Particle Systems.” Physical Review Letters. American Physical Society, 2018. https://doi.org/10.1103/physrevlett.121.165301. ieee: G. Bighin, T. Tscherbul, and M. Lemeshko, “Diagrammatic Monte Carlo approach to angular momentum in quantum many-particle systems,” Physical Review Letters, vol. 121, no. 16. American Physical Society, 2018. ista: Bighin G, Tscherbul T, Lemeshko M. 2018. Diagrammatic Monte Carlo approach to angular momentum in quantum many-particle systems. Physical Review Letters. 121(16), 165301. mla: Bighin, Giacomo, et al. “Diagrammatic Monte Carlo Approach to Angular Momentum in Quantum Many-Particle Systems.” Physical Review Letters, vol. 121, no. 16, 165301, American Physical Society, 2018, doi:10.1103/physrevlett.121.165301. short: G. Bighin, T. Tscherbul, M. Lemeshko, Physical Review Letters 121 (2018). date_created: 2019-04-17T10:53:38Z date_published: 2018-10-16T00:00:00Z date_updated: 2024-02-28T13:15:09Z day: '16' department: - _id: MiLe doi: 10.1103/physrevlett.121.165301 external_id: arxiv: - '1803.07990' isi: - '000447468400008' intvolume: ' 121' isi: 1 issue: '16' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1803.07990 month: '10' oa: 1 oa_version: Preprint project: - _id: 26031614-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P29902 name: Quantum rotations in the presence of a many-body environment publication: Physical Review Letters publication_status: published publisher: American Physical Society quality_controlled: '1' related_material: link: - description: News on IST Homepage relation: press_release url: https://ist.ac.at/en/news/description-of-rotating-molecules-made-easy/ scopus_import: '1' status: public title: Diagrammatic Monte Carlo approach to angular momentum in quantum many-particle systems type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 121 year: '2018' ... --- _id: '417' abstract: - lang: eng text: 'We introduce a Diagrammatic Monte Carlo (DiagMC) approach to complex molecular impurities with rotational degrees of freedom interacting with a many-particle environment. The treatment is based on the diagrammatic expansion that merges the usual Feynman diagrams with the angular momentum diagrams known from atomic and nuclear structure theory, thereby incorporating the non-Abelian algebra inherent to quantum rotations. Our approach works at arbitrary coupling, is free of systematic errors and of finite size effects, and naturally provides access to the impurity Green function. We exemplify the technique by obtaining an all-coupling solution of the angulon model, however, the method is quite general and can be applied to a broad variety of quantum impurities possessing angular momentum degrees of freedom. ' article_number: '165301' article_processing_charge: No author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Timur full_name: Tscherbul, Timur last_name: Tscherbul - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 citation: ama: Bighin G, Tscherbul T, Lemeshko M. Diagrammatic Monte Carlo approach to rotating molecular impurities. Physical Review Letters. 2018;121(16). doi:10.1103/PhysRevLett.121.165301 apa: Bighin, G., Tscherbul, T., & Lemeshko, M. (2018). Diagrammatic Monte Carlo approach to rotating molecular impurities. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.121.165301 chicago: Bighin, Giacomo, Timur Tscherbul, and Mikhail Lemeshko. “Diagrammatic Monte Carlo Approach to Rotating Molecular Impurities.” Physical Review Letters. American Physical Society, 2018. https://doi.org/10.1103/PhysRevLett.121.165301. ieee: G. Bighin, T. Tscherbul, and M. Lemeshko, “Diagrammatic Monte Carlo approach to rotating molecular impurities,” Physical Review Letters, vol. 121, no. 16. American Physical Society, 2018. ista: Bighin G, Tscherbul T, Lemeshko M. 2018. Diagrammatic Monte Carlo approach to rotating molecular impurities. Physical Review Letters. 121(16), 165301. mla: Bighin, Giacomo, et al. “Diagrammatic Monte Carlo Approach to Rotating Molecular Impurities.” Physical Review Letters, vol. 121, no. 16, 165301, American Physical Society, 2018, doi:10.1103/PhysRevLett.121.165301. short: G. Bighin, T. Tscherbul, M. Lemeshko, Physical Review Letters 121 (2018). date_created: 2018-12-11T11:46:22Z date_published: 2018-10-16T00:00:00Z date_updated: 2024-02-28T13:14:53Z day: '16' department: - _id: MiLe doi: 10.1103/PhysRevLett.121.165301 external_id: arxiv: - '1803.07990' intvolume: ' 121' issue: '16' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1803.07990 month: '10' oa: 1 oa_version: Preprint project: - _id: 26031614-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P29902 name: Quantum rotations in the presence of a many-body environment publication: Physical Review Letters publication_status: published publisher: American Physical Society publist_id: '8025' quality_controlled: '1' scopus_import: '1' status: public title: Diagrammatic Monte Carlo approach to rotating molecular impurities type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 121 year: '2018' ... --- _id: '1015' abstract: - lang: eng text: 'Vortices are commonly observed in the context of classical hydrodynamics: from whirlpools after stirring the coffee in a cup to a violent atmospheric phenomenon such as a tornado, all classical vortices are characterized by an arbitrary circulation value of the local velocity field. On the other hand the appearance of vortices with quantized circulation represents one of the fundamental signatures of macroscopic quantum phenomena. In two-dimensional superfluids quantized vortices play a key role in determining finite-temperature properties, as the superfluid phase and the normal state are separated by a vortex unbinding transition, the Berezinskii-Kosterlitz-Thouless transition. Very recent experiments with two-dimensional superfluid fermions motivate the present work: we present theoretical results based on the renormalization group showing that the universal jump of the superfluid density and the critical temperature crucially depend on the interaction strength, providing a strong benchmark for forthcoming investigations.' article_number: '45702' article_processing_charge: No author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Luca full_name: Salasnich, Luca last_name: Salasnich citation: ama: Bighin G, Salasnich L. Vortices and antivortices in two-dimensional ultracold Fermi gases. Scientific Reports. 2017;7. doi:10.1038/srep45702 apa: Bighin, G., & Salasnich, L. (2017). Vortices and antivortices in two-dimensional ultracold Fermi gases. Scientific Reports. Nature Publishing Group. https://doi.org/10.1038/srep45702 chicago: Bighin, Giacomo, and Luca Salasnich. “Vortices and Antivortices in Two-Dimensional Ultracold Fermi Gases.” Scientific Reports. Nature Publishing Group, 2017. https://doi.org/10.1038/srep45702. ieee: G. Bighin and L. Salasnich, “Vortices and antivortices in two-dimensional ultracold Fermi gases,” Scientific Reports, vol. 7. Nature Publishing Group, 2017. ista: Bighin G, Salasnich L. 2017. Vortices and antivortices in two-dimensional ultracold Fermi gases. Scientific Reports. 7, 45702. mla: Bighin, Giacomo, and Luca Salasnich. “Vortices and Antivortices in Two-Dimensional Ultracold Fermi Gases.” Scientific Reports, vol. 7, 45702, Nature Publishing Group, 2017, doi:10.1038/srep45702. short: G. Bighin, L. Salasnich, Scientific Reports 7 (2017). date_created: 2018-12-11T11:49:42Z date_published: 2017-04-04T00:00:00Z date_updated: 2023-09-22T09:43:10Z day: '04' ddc: - '539' department: - _id: MiLe doi: 10.1038/srep45702 external_id: isi: - '000398148100001' file: - access_level: open_access content_type: application/pdf creator: system date_created: 2018-12-12T10:12:32Z date_updated: 2018-12-12T10:12:32Z file_id: '4950' file_name: IST-2017-809-v1+1_srep45702.pdf file_size: 478289 relation: main_file file_date_updated: 2018-12-12T10:12:32Z has_accepted_license: '1' intvolume: ' 7' isi: 1 language: - iso: eng month: '04' oa: 1 oa_version: Published Version publication: Scientific Reports publication_identifier: issn: - '20452322' publication_status: published publisher: Nature Publishing Group publist_id: '6380' pubrep_id: '809' quality_controlled: '1' scopus_import: '1' status: public title: Vortices and antivortices in two-dimensional ultracold Fermi gases tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 7 year: '2017' ... --- _id: '995' abstract: - lang: eng text: Recently it was shown that an impurity exchanging orbital angular momentum with a surrounding bath can be described in terms of the angulon quasiparticle [Phys. Rev. Lett. 118, 095301 (2017)]. The angulon consists of a quantum rotor dressed by a many-particle field of boson excitations, and can be formed out of, for example, a molecule or a nonspherical atom in superfluid helium, or out of an electron coupled to lattice phonons or a Bose condensate. Here we develop an approach to the angulon based on the path-integral formalism, which sets the ground for a systematic, perturbative treatment of the angulon problem. The resulting perturbation series can be interpreted in terms of Feynman diagrams, from which, in turn, one can derive a set of diagrammatic rules. These rules extend the machinery of the graphical theory of angular momentum - well known from theoretical atomic spectroscopy - to the case where an environment with an infinite number of degrees of freedom is present. In particular, we show that each diagram can be interpreted as a 'skeleton', which enforces angular momentum conservation, dressed by an additional many-body contribution. This connection between the angulon theory and the graphical theory of angular momentum is particularly important as it allows to systematically and substantially simplify the analytical representation of each diagram. In order to exemplify the technique, we calculate the 1- and 2-loop contributions to the angulon self-energy, the spectral function, and the quasiparticle weight. The diagrammatic theory we develop paves the way to investigate next-to-leading order quantities in a more compact way compared to the variational approaches. article_number: '085410' article_processing_charge: No author: - first_name: Giacomo full_name: Bighin, Giacomo id: 4CA96FD4-F248-11E8-B48F-1D18A9856A87 last_name: Bighin orcid: 0000-0001-8823-9777 - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 citation: ama: Bighin G, Lemeshko M. Diagrammatic approach to orbital quantum impurities interacting with a many-particle environment. Physical Review B - Condensed Matter and Materials Physics. 2017;96(8). doi:10.1103/PhysRevB.96.085410 apa: Bighin, G., & Lemeshko, M. (2017). Diagrammatic approach to orbital quantum impurities interacting with a many-particle environment. Physical Review B - Condensed Matter and Materials Physics. American Physical Society. https://doi.org/10.1103/PhysRevB.96.085410 chicago: Bighin, Giacomo, and Mikhail Lemeshko. “Diagrammatic Approach to Orbital Quantum Impurities Interacting with a Many-Particle Environment.” Physical Review B - Condensed Matter and Materials Physics. American Physical Society, 2017. https://doi.org/10.1103/PhysRevB.96.085410. ieee: G. Bighin and M. Lemeshko, “Diagrammatic approach to orbital quantum impurities interacting with a many-particle environment,” Physical Review B - Condensed Matter and Materials Physics, vol. 96, no. 8. American Physical Society, 2017. ista: Bighin G, Lemeshko M. 2017. Diagrammatic approach to orbital quantum impurities interacting with a many-particle environment. Physical Review B - Condensed Matter and Materials Physics. 96(8), 085410. mla: Bighin, Giacomo, and Mikhail Lemeshko. “Diagrammatic Approach to Orbital Quantum Impurities Interacting with a Many-Particle Environment.” Physical Review B - Condensed Matter and Materials Physics, vol. 96, no. 8, 085410, American Physical Society, 2017, doi:10.1103/PhysRevB.96.085410. short: G. Bighin, M. Lemeshko, Physical Review B - Condensed Matter and Materials Physics 96 (2017). date_created: 2018-12-11T11:49:36Z date_published: 2017-08-07T00:00:00Z date_updated: 2023-09-22T09:53:17Z day: '07' department: - _id: MiLe doi: 10.1103/PhysRevB.96.085410 external_id: isi: - '000407017100009' intvolume: ' 96' isi: 1 issue: '8' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1704.02616 month: '08' oa: 1 oa_version: Submitted Version project: - _id: 26031614-B435-11E9-9278-68D0E5697425 call_identifier: FWF grant_number: P29902 name: Quantum rotations in the presence of a many-body environment publication: Physical Review B - Condensed Matter and Materials Physics publication_identifier: issn: - '24699950' publication_status: published publisher: American Physical Society publist_id: '6404' quality_controlled: '1' scopus_import: '1' status: public title: Diagrammatic approach to orbital quantum impurities interacting with a many-particle environment type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 96 year: '2017' ...