--- _id: '13275' abstract: - lang: eng text: We introduce a generic and accessible implementation of an exact diagonalization method for studying few-fermion models. Our aim is to provide a testbed for the newcomers to the field as well as a stepping stone for trying out novel optimizations and approximations. This userguide consists of a description of the algorithm, and several examples in varying orders of sophistication. In particular, we exemplify our routine using an effective-interaction approach that fixes the low-energy physics. We benchmark this approach against the existing data, and show that it is able to deliver state-of-the-art numerical results at a significantly reduced computational cost. article_processing_charge: No author: - first_name: Lukas full_name: Rammelmüller, Lukas last_name: Rammelmüller - first_name: David full_name: Huber, David last_name: Huber - first_name: Artem full_name: Volosniev, Artem id: 37D278BC-F248-11E8-B48F-1D18A9856A87 last_name: Volosniev orcid: 0000-0003-0393-5525 citation: ama: Rammelmüller L, Huber D, Volosniev A. Codebase release 1.0 for FermiFCI. 2023. doi:10.21468/scipostphyscodeb.12-r1.0 apa: Rammelmüller, L., Huber, D., & Volosniev, A. (2023). Codebase release 1.0 for FermiFCI. SciPost Foundation. https://doi.org/10.21468/scipostphyscodeb.12-r1.0 chicago: Rammelmüller, Lukas, David Huber, and Artem Volosniev. “Codebase Release 1.0 for FermiFCI.” SciPost Foundation, 2023. https://doi.org/10.21468/scipostphyscodeb.12-r1.0. ieee: L. Rammelmüller, D. Huber, and A. Volosniev, “Codebase release 1.0 for FermiFCI.” SciPost Foundation, 2023. ista: Rammelmüller L, Huber D, Volosniev A. 2023. Codebase release 1.0 for FermiFCI, SciPost Foundation, 10.21468/scipostphyscodeb.12-r1.0. mla: Rammelmüller, Lukas, et al. Codebase Release 1.0 for FermiFCI. SciPost Foundation, 2023, doi:10.21468/scipostphyscodeb.12-r1.0. short: L. Rammelmüller, D. Huber, A. Volosniev, (2023). date_created: 2023-07-24T10:46:23Z date_published: 2023-04-19T00:00:00Z date_updated: 2023-07-31T09:16:02Z day: '19' ddc: - '530' department: - _id: MiLe doi: 10.21468/scipostphyscodeb.12-r1.0 ec_funded: 1 main_file_link: - open_access: '1' url: https://doi.org/10.21468/SciPostPhysCodeb.12-r1.0 month: '04' oa: 1 oa_version: Published Version project: - _id: 260C2330-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '754411' name: ISTplus - Postdoctoral Fellowships publisher: SciPost Foundation related_material: record: - id: '13276' relation: used_in_publication status: public status: public title: Codebase release 1.0 for FermiFCI type: research_data_reference user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2023' ... --- _id: '12723' abstract: - lang: eng text: 'Lead halide perovskites enjoy a number of remarkable optoelectronic properties. To explain their origin, it is necessary to study how electromagnetic fields interact with these systems. We address this problem here by studying two classical quantities: Faraday rotation and the complex refractive index in a paradigmatic perovskite CH3NH3PbBr3 in a broad wavelength range. We find that the minimal coupling of electromagnetic fields to the k⋅p Hamiltonian is insufficient to describe the observed data even on the qualitative level. To amend this, we demonstrate that there exists a relevant atomic-level coupling between electromagnetic fields and the spin degree of freedom. This spin-electric coupling allows for quantitative description of a number of previous as well as present experimental data. In particular, we use it here to show that the Faraday effect in lead halide perovskites is dominated by the Zeeman splitting of the energy levels and has a substantial beyond-Becquerel contribution. Finally, we present general symmetry-based phenomenological arguments that in the low-energy limit our effective model includes all basis coupling terms to the electromagnetic field in the linear order.' article_number: '106901' 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: Abhishek full_name: Shiva Kumar, Abhishek id: 5e9a6931-eb97-11eb-a6c2-e96f7058d77a last_name: Shiva Kumar - first_name: Dusan full_name: Lorenc, Dusan id: 40D8A3E6-F248-11E8-B48F-1D18A9856A87 last_name: Lorenc - first_name: Younes full_name: Ashourishokri, Younes id: e32c111f-f6e0-11ea-865d-eb955baea334 last_name: Ashourishokri - first_name: Ayan A. full_name: Zhumekenov, Ayan A. last_name: Zhumekenov - first_name: Osman M. full_name: Bakr, Osman M. last_name: Bakr - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 citation: ama: Volosniev A, Shiva Kumar A, Lorenc D, et al. Spin-electric coupling in lead halide perovskites. Physical Review Letters. 2023;130(10). doi:10.1103/physrevlett.130.106901 apa: Volosniev, A., Shiva Kumar, A., Lorenc, D., Ashourishokri, Y., Zhumekenov, A. A., Bakr, O. M., … Alpichshev, Z. (2023). Spin-electric coupling in lead halide perovskites. Physical Review Letters. American Physical Society. https://doi.org/10.1103/physrevlett.130.106901 chicago: Volosniev, Artem, Abhishek Shiva Kumar, Dusan Lorenc, Younes Ashourishokri, Ayan A. Zhumekenov, Osman M. Bakr, Mikhail Lemeshko, and Zhanybek Alpichshev. “Spin-Electric Coupling in Lead Halide Perovskites.” Physical Review Letters. American Physical Society, 2023. https://doi.org/10.1103/physrevlett.130.106901. ieee: A. Volosniev et al., “Spin-electric coupling in lead halide perovskites,” Physical Review Letters, vol. 130, no. 10. American Physical Society, 2023. ista: Volosniev A, Shiva Kumar A, Lorenc D, Ashourishokri Y, Zhumekenov AA, Bakr OM, Lemeshko M, Alpichshev Z. 2023. Spin-electric coupling in lead halide perovskites. Physical Review Letters. 130(10), 106901. mla: Volosniev, Artem, et al. “Spin-Electric Coupling in Lead Halide Perovskites.” Physical Review Letters, vol. 130, no. 10, 106901, American Physical Society, 2023, doi:10.1103/physrevlett.130.106901. short: A. Volosniev, A. Shiva Kumar, D. Lorenc, Y. Ashourishokri, A.A. Zhumekenov, O.M. Bakr, M. Lemeshko, Z. Alpichshev, Physical Review Letters 130 (2023). date_created: 2023-03-14T13:11:59Z date_published: 2023-03-10T00:00:00Z date_updated: 2023-08-01T13:39:04Z day: '10' department: - _id: GradSch - _id: ZhAl - _id: MiLe doi: 10.1103/physrevlett.130.106901 external_id: arxiv: - '2203.09443' isi: - '000982435900002' intvolume: ' 130' isi: 1 issue: '10' keyword: - General Physics and Astronomy language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2203.09443 month: '03' oa: 1 oa_version: Preprint publication: Physical Review Letters publication_identifier: eissn: - 1079-7114 issn: - 0031-9007 publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: Spin-electric coupling in lead halide perovskites type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 130 year: '2023' ... --- _id: '12724' abstract: - lang: eng text: 'We use general symmetry-based arguments to construct an effective model suitable for studying optical properties of lead halide perovskites. To build the model, we identify an atomic-level interaction between electromagnetic fields and the spin degree of freedom that should be added to a minimally coupled k⋅p Hamiltonian. As a first application, we study two basic optical characteristics of the material: the Verdet constant and the refractive index. Beyond these linear characteristics of the material, the model is suitable for calculating nonlinear effects such as the third-order optical susceptibility. Analysis of this quantity shows that the geometrical properties of the spin-electric term imply isotropic optical response of the system, and that optical anisotropy of lead halide perovskites is a manifestation of hopping of charge carriers. To illustrate this, we discuss third-harmonic generation.' article_number: '125201' 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: Abhishek full_name: Shiva Kumar, Abhishek id: 5e9a6931-eb97-11eb-a6c2-e96f7058d77a last_name: Shiva Kumar - first_name: Dusan full_name: Lorenc, Dusan id: 40D8A3E6-F248-11E8-B48F-1D18A9856A87 last_name: Lorenc - first_name: Younes full_name: Ashourishokri, Younes id: e32c111f-f6e0-11ea-865d-eb955baea334 last_name: Ashourishokri - first_name: Ayan full_name: Zhumekenov, Ayan last_name: Zhumekenov - first_name: Osman M. full_name: Bakr, Osman M. last_name: Bakr - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 citation: ama: Volosniev A, Shiva Kumar A, Lorenc D, et al. Effective model for studying optical properties of lead halide perovskites. Physical Review B. 2023;107(12). doi:10.1103/physrevb.107.125201 apa: Volosniev, A., Shiva Kumar, A., Lorenc, D., Ashourishokri, Y., Zhumekenov, A., Bakr, O. M., … Alpichshev, Z. (2023). Effective model for studying optical properties of lead halide perovskites. Physical Review B. American Physical Society. https://doi.org/10.1103/physrevb.107.125201 chicago: Volosniev, Artem, Abhishek Shiva Kumar, Dusan Lorenc, Younes Ashourishokri, Ayan Zhumekenov, Osman M. Bakr, Mikhail Lemeshko, and Zhanybek Alpichshev. “Effective Model for Studying Optical Properties of Lead Halide Perovskites.” Physical Review B. American Physical Society, 2023. https://doi.org/10.1103/physrevb.107.125201. ieee: A. Volosniev et al., “Effective model for studying optical properties of lead halide perovskites,” Physical Review B, vol. 107, no. 12. American Physical Society, 2023. ista: Volosniev A, Shiva Kumar A, Lorenc D, Ashourishokri Y, Zhumekenov A, Bakr OM, Lemeshko M, Alpichshev Z. 2023. Effective model for studying optical properties of lead halide perovskites. Physical Review B. 107(12), 125201. mla: Volosniev, Artem, et al. “Effective Model for Studying Optical Properties of Lead Halide Perovskites.” Physical Review B, vol. 107, no. 12, 125201, American Physical Society, 2023, doi:10.1103/physrevb.107.125201. short: A. Volosniev, A. Shiva Kumar, D. Lorenc, Y. Ashourishokri, A. Zhumekenov, O.M. Bakr, M. Lemeshko, Z. Alpichshev, Physical Review B 107 (2023). date_created: 2023-03-14T13:13:05Z date_published: 2023-03-15T00:00:00Z date_updated: 2023-08-01T13:39:47Z day: '15' department: - _id: GradSch - _id: ZhAl - _id: MiLe doi: 10.1103/physrevb.107.125201 external_id: arxiv: - '2204.04022' isi: - '000972602200006' intvolume: ' 107' isi: 1 issue: '12' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2204.04022 month: '03' oa: 1 oa_version: Preprint 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: Effective model for studying optical properties of lead halide perovskites type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 107 year: '2023' ... --- _id: '12788' abstract: - lang: eng text: We show that the simplest of existing molecules—closed-shell diatomics not interacting with one another—host topological charges when driven by periodic far-off-resonant laser pulses. A periodically kicked molecular rotor can be mapped onto a “crystalline” lattice in angular momentum space. This allows us to define quasimomenta and the band structure in the Floquet representation, by analogy with the Bloch waves of solid-state physics. Applying laser pulses spaced by 1/3 of the molecular rotational period creates a lattice with three atoms per unit cell with staggered hopping. Within the synthetic dimension of the laser strength, we discover Dirac cones with topological charges. These Dirac cones, topologically protected by reflection and time-reversal symmetry, are reminiscent of (although not equivalent to) that seen in graphene. They—and the corresponding edge states—are broadly tunable by adjusting the laser strength and can be observed in present-day experiments by measuring molecular alignment and populations of rotational levels. This paves the way to study controllable topological physics in gas-phase experiments with small molecules as well as to classify dynamical molecular states by their topological invariants. acknowledgement: M. L. acknowledges support by the European Research Council (ERC) Starting Grant No. 801770 (ANGULON). article_number: '103202' article_processing_charge: No article_type: original author: - first_name: Volker full_name: Karle, Volker id: D7C012AE-D7ED-11E9-95E8-1EC5E5697425 last_name: Karle - first_name: Areg full_name: Ghazaryan, Areg id: 4AF46FD6-F248-11E8-B48F-1D18A9856A87 last_name: Ghazaryan orcid: 0000-0001-9666-3543 - first_name: Mikhail full_name: Lemeshko, Mikhail id: 37CB05FA-F248-11E8-B48F-1D18A9856A87 last_name: Lemeshko orcid: 0000-0002-6990-7802 citation: ama: Karle V, Ghazaryan A, Lemeshko M. Topological charges of periodically kicked molecules. Physical Review Letters. 2023;130(10). doi:10.1103/PhysRevLett.130.103202 apa: Karle, V., Ghazaryan, A., & Lemeshko, M. (2023). Topological charges of periodically kicked molecules. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.130.103202 chicago: Karle, Volker, Areg Ghazaryan, and Mikhail Lemeshko. “Topological Charges of Periodically Kicked Molecules.” Physical Review Letters. American Physical Society, 2023. https://doi.org/10.1103/PhysRevLett.130.103202. ieee: V. Karle, A. Ghazaryan, and M. Lemeshko, “Topological charges of periodically kicked molecules,” Physical Review Letters, vol. 130, no. 10. American Physical Society, 2023. ista: Karle V, Ghazaryan A, Lemeshko M. 2023. Topological charges of periodically kicked molecules. Physical Review Letters. 130(10), 103202. mla: Karle, Volker, et al. “Topological Charges of Periodically Kicked Molecules.” Physical Review Letters, vol. 130, no. 10, 103202, American Physical Society, 2023, doi:10.1103/PhysRevLett.130.103202. short: V. Karle, A. Ghazaryan, M. Lemeshko, Physical Review Letters 130 (2023). date_created: 2023-04-02T22:01:10Z date_published: 2023-03-10T00:00:00Z date_updated: 2023-08-01T14:02:06Z day: '10' department: - _id: MiLe doi: 10.1103/PhysRevLett.130.103202 ec_funded: 1 external_id: arxiv: - '2206.07067' isi: - '000957635500003' intvolume: ' 130' isi: 1 issue: '10' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2206.07067 month: '03' oa: 1 oa_version: Preprint project: - _id: 2688CF98-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '801770' name: 'Angulon: physics and applications of a new quasiparticle' 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 on the ISTA website relation: press_release url: https://ista.ac.at/en/news/topology-of-rotating-molecules/ scopus_import: '1' status: public title: Topological charges of periodically kicked molecules type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 130 year: '2023' ... --- _id: '12790' abstract: - lang: eng text: Motivated by the recent discoveries of superconductivity in bilayer and trilayer graphene, we theoretically investigate superconductivity and other interaction-driven phases in multilayer graphene stacks. To this end, we study the density of states of multilayer graphene with up to four layers at the single-particle band structure level in the presence of a transverse electric field. Among the considered structures, tetralayer graphene with rhombohedral (ABCA) stacking reaches the highest density of states. We study the phases that can arise in ABCA graphene by tuning the carrier density and transverse electric field. For a broad region of the tuning parameters, the presence of strong Coulomb repulsion leads to a spontaneous spin and valley symmetry breaking via Stoner transitions. Using a model that incorporates the spontaneous spin and valley polarization, we explore the Kohn-Luttinger mechanism for superconductivity driven by repulsive Coulomb interactions. We find that the strongest superconducting instability is in the p-wave channel, and occurs in proximity to the onset of Stoner transitions. Interestingly, we find a range of densities and transverse electric fields where superconductivity develops out of a strongly corrugated, singly connected Fermi surface in each valley, leading to a topologically nontrivial chiral p+ip superconducting state with an even number of copropagating chiral Majorana edge modes. Our work establishes ABCA-stacked tetralayer graphene as a promising platform for observing strongly correlated physics and topological superconductivity. acknowledgement: E.B. and T.H. were supported by the European Research Council (ERC) under grant HQMAT (Grant Agreement No. 817799), by the Israel-USA Binational Science Foundation (BSF), and by a Research grant from Irving and Cherna Moskowitz. article_number: '104502' article_processing_charge: No article_type: original author: - first_name: Areg full_name: Ghazaryan, Areg id: 4AF46FD6-F248-11E8-B48F-1D18A9856A87 last_name: Ghazaryan orcid: 0000-0001-9666-3543 - first_name: Tobias full_name: Holder, Tobias last_name: Holder - first_name: Erez full_name: Berg, Erez last_name: Berg - first_name: Maksym full_name: Serbyn, Maksym id: 47809E7E-F248-11E8-B48F-1D18A9856A87 last_name: Serbyn orcid: 0000-0002-2399-5827 citation: ama: Ghazaryan A, Holder T, Berg E, Serbyn M. Multilayer graphenes as a platform for interaction-driven physics and topological superconductivity. Physical Review B. 2023;107(10). doi:10.1103/PhysRevB.107.104502 apa: Ghazaryan, A., Holder, T., Berg, E., & Serbyn, M. (2023). Multilayer graphenes as a platform for interaction-driven physics and topological superconductivity. Physical Review B. American Physical Society. https://doi.org/10.1103/PhysRevB.107.104502 chicago: Ghazaryan, Areg, Tobias Holder, Erez Berg, and Maksym Serbyn. “Multilayer Graphenes as a Platform for Interaction-Driven Physics and Topological Superconductivity.” Physical Review B. American Physical Society, 2023. https://doi.org/10.1103/PhysRevB.107.104502. ieee: A. Ghazaryan, T. Holder, E. Berg, and M. Serbyn, “Multilayer graphenes as a platform for interaction-driven physics and topological superconductivity,” Physical Review B, vol. 107, no. 10. American Physical Society, 2023. ista: Ghazaryan A, Holder T, Berg E, Serbyn M. 2023. Multilayer graphenes as a platform for interaction-driven physics and topological superconductivity. Physical Review B. 107(10), 104502. mla: Ghazaryan, Areg, et al. “Multilayer Graphenes as a Platform for Interaction-Driven Physics and Topological Superconductivity.” Physical Review B, vol. 107, no. 10, 104502, American Physical Society, 2023, doi:10.1103/PhysRevB.107.104502. short: A. Ghazaryan, T. Holder, E. Berg, M. Serbyn, Physical Review B 107 (2023). date_created: 2023-04-02T22:01:10Z date_published: 2023-03-01T00:00:00Z date_updated: 2023-08-01T13:59:29Z day: '01' department: - _id: MaSe - _id: MiLe doi: 10.1103/PhysRevB.107.104502 external_id: arxiv: - '2211.02492' isi: - '000945526400003' intvolume: ' 107' isi: 1 issue: '10' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.48550/arXiv.2211.02492 month: '03' oa: 1 oa_version: Preprint publication: Physical Review B publication_identifier: eissn: - 2469-9969 issn: - 2469-9950 publication_status: published publisher: American Physical Society quality_controlled: '1' related_material: link: - description: News on the ISTA website relation: press_release url: https://ista.ac.at/en/news/reaching-superconductivity-layer-by-layer/ scopus_import: '1' status: public title: Multilayer graphenes as a platform for interaction-driven physics and topological superconductivity type: journal_article user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8 volume: 107 year: '2023' ...