--- _id: '14886' abstract: - lang: eng text: It is a basic principle that an effect cannot come before the cause. Dispersive relations that follow from this fundamental fact have proven to be an indispensable tool in physics and engineering. They are most powerful in the domain of linear response where they are known as Kramers-Kronig relations. However, when it comes to nonlinear phenomena the implications of causality are much less explored, apart from several notable exceptions. Here in this paper we demonstrate how to apply the dispersive formalism to analyze the ultrafast nonlinear response in the context of the paradigmatic nonlinear Kerr effect. We find that the requirement of causality introduces a noticeable effect even under assumption that Kerr effect is mediated by quasi-instantaneous off-resonant electronic hyperpolarizability. We confirm this by experimentally measuring the time-resolved Kerr dynamics in GaAs by means of a hybrid pump-probe Mach-Zehnder interferometer and demonstrate the presence of an intrinsic lagging between amplitude and phase responses as predicted by dispersive analysis. Our results describe a general property of the time-resolved nonlinear processes thereby highlighting the importance of accounting for dispersive effects in the nonlinear optical processes involving ultrashort pulses. acknowledgement: The work was supported by the Institute of Science and Technology Austria (ISTA). We thank Prof. John M. Dudley, Dr. Ugur Sezer, and Dr. Artem Volosniev for valuable discussions. article_number: '013042' article_processing_charge: Yes article_type: original author: - first_name: Dusan full_name: Lorenc, Dusan id: 40D8A3E6-F248-11E8-B48F-1D18A9856A87 last_name: Lorenc - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 citation: ama: 'Lorenc D, Alpichshev Z. Dispersive effects in ultrafast nonlinear phenomena: The case of optical Kerr effect. Physical Review Research. 2024;6(1). doi:10.1103/PhysRevResearch.6.013042' apa: 'Lorenc, D., & Alpichshev, Z. (2024). Dispersive effects in ultrafast nonlinear phenomena: The case of optical Kerr effect. Physical Review Research. American Physical Society. https://doi.org/10.1103/PhysRevResearch.6.013042' chicago: 'Lorenc, Dusan, and Zhanybek Alpichshev. “Dispersive Effects in Ultrafast Nonlinear Phenomena: The Case of Optical Kerr Effect.” Physical Review Research. American Physical Society, 2024. https://doi.org/10.1103/PhysRevResearch.6.013042.' ieee: 'D. Lorenc and Z. Alpichshev, “Dispersive effects in ultrafast nonlinear phenomena: The case of optical Kerr effect,” Physical Review Research, vol. 6, no. 1. American Physical Society, 2024.' ista: 'Lorenc D, Alpichshev Z. 2024. Dispersive effects in ultrafast nonlinear phenomena: The case of optical Kerr effect. Physical Review Research. 6(1), 013042.' mla: 'Lorenc, Dusan, and Zhanybek Alpichshev. “Dispersive Effects in Ultrafast Nonlinear Phenomena: The Case of Optical Kerr Effect.” Physical Review Research, vol. 6, no. 1, 013042, American Physical Society, 2024, doi:10.1103/PhysRevResearch.6.013042.' short: D. Lorenc, Z. Alpichshev, Physical Review Research 6 (2024). date_created: 2024-01-28T23:01:42Z date_published: 2024-01-11T00:00:00Z date_updated: 2024-01-31T12:01:16Z day: '11' ddc: - '530' department: - _id: ZhAl doi: 10.1103/PhysRevResearch.6.013042 file: - access_level: open_access checksum: 42d58f93ae74e7f2c4de058ef75ff8b2 content_type: application/pdf creator: dernst date_created: 2024-01-31T11:59:30Z date_updated: 2024-01-31T11:59:30Z file_id: '14918' file_name: 2024_PhysicalReviewResearch_Lorenc.pdf file_size: 2863627 relation: main_file success: 1 file_date_updated: 2024-01-31T11:59:30Z has_accepted_license: '1' intvolume: ' 6' issue: '1' language: - iso: eng license: https://creativecommons.org/licenses/by/4.0/ month: '01' oa: 1 oa_version: Published Version publication: Physical Review Research publication_identifier: eissn: - 2643-1564 publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: 'Dispersive effects in ultrafast nonlinear phenomena: The case of optical Kerr effect' 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: 6 year: '2024' ... --- _id: '13251' abstract: - lang: eng text: A rotating organic cation and a dynamically disordered soft inorganic cage are the hallmark features of organic-inorganic lead-halide perovskites. Understanding the interplay between these two subsystems is a challenging problem, but it is this coupling that is widely conjectured to be responsible for the unique behavior of photocarriers in these materials. In this work, we use the fact that the polarizability of the organic cation strongly depends on the ambient electrostatic environment to put the molecule forward as a sensitive probe of the local crystal fields inside the lattice cell. We measure the average polarizability of the C/N–H bond stretching mode by means of infrared spectroscopy, which allows us to deduce the character of the motion of the cation molecule, find the magnitude of the local crystal field, and place an estimate on the strength of the hydrogen bond between the hydrogen and halide atoms. Our results pave the way for understanding electric fields in lead-halide perovskites using infrared bond spectroscopy. acknowledgement: "We thank Bingqing Cheng and Hong-Zhou Ye for valuable discussions; Y.W.’s work at IST Austria was supported through ISTernship summer internship program funded by OeADGmbH; D.L. and Z.A. acknowledge support by IST Austria (ISTA); M.L. acknowledges support by the European Research Council (ERC) Starting Grant No. 801770 (ANGULON).\r\nA.A.Z. and O.M.B. acknowledge support by KAUST." article_processing_charge: Yes (via OA deal) article_type: original author: - first_name: Yujing full_name: Wei, Yujing id: 0c5ff007-2600-11ee-b896-98bd8d663294 last_name: Wei orcid: 0000-0001-8913-9719 - first_name: Artem full_name: Volosniev, Artem id: 37D278BC-F248-11E8-B48F-1D18A9856A87 last_name: Volosniev orcid: 0000-0003-0393-5525 - first_name: Dusan full_name: Lorenc, Dusan id: 40D8A3E6-F248-11E8-B48F-1D18A9856A87 last_name: Lorenc - 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: Wei Y, Volosniev A, Lorenc D, et al. Bond polarizability as a probe of local crystal fields in hybrid lead-halide perovskites. The Journal of Physical Chemistry Letters. 2023;14(27):6309-6314. doi:10.1021/acs.jpclett.3c01158 apa: Wei, Y., Volosniev, A., Lorenc, D., Zhumekenov, A. A., Bakr, O. M., Lemeshko, M., & Alpichshev, Z. (2023). Bond polarizability as a probe of local crystal fields in hybrid lead-halide perovskites. The Journal of Physical Chemistry Letters. American Chemical Society. https://doi.org/10.1021/acs.jpclett.3c01158 chicago: Wei, Yujing, Artem Volosniev, Dusan Lorenc, Ayan A. Zhumekenov, Osman M. Bakr, Mikhail Lemeshko, and Zhanybek Alpichshev. “Bond Polarizability as a Probe of Local Crystal Fields in Hybrid Lead-Halide Perovskites.” The Journal of Physical Chemistry Letters. American Chemical Society, 2023. https://doi.org/10.1021/acs.jpclett.3c01158. ieee: Y. Wei et al., “Bond polarizability as a probe of local crystal fields in hybrid lead-halide perovskites,” The Journal of Physical Chemistry Letters, vol. 14, no. 27. American Chemical Society, pp. 6309–6314, 2023. ista: Wei Y, Volosniev A, Lorenc D, Zhumekenov AA, Bakr OM, Lemeshko M, Alpichshev Z. 2023. Bond polarizability as a probe of local crystal fields in hybrid lead-halide perovskites. The Journal of Physical Chemistry Letters. 14(27), 6309–6314. mla: Wei, Yujing, et al. “Bond Polarizability as a Probe of Local Crystal Fields in Hybrid Lead-Halide Perovskites.” The Journal of Physical Chemistry Letters, vol. 14, no. 27, American Chemical Society, 2023, pp. 6309–14, doi:10.1021/acs.jpclett.3c01158. short: Y. Wei, A. Volosniev, D. Lorenc, A.A. Zhumekenov, O.M. Bakr, M. Lemeshko, Z. Alpichshev, The Journal of Physical Chemistry Letters 14 (2023) 6309–6314. date_created: 2023-07-18T11:13:17Z date_published: 2023-07-05T00:00:00Z date_updated: 2023-07-19T06:59:19Z day: '05' ddc: - '530' department: - _id: MiLe - _id: ZhAl doi: 10.1021/acs.jpclett.3c01158 ec_funded: 1 external_id: arxiv: - '2304.14198' isi: - '001022811500001' file: - access_level: open_access checksum: c0c040063f06a51b9c463adc504f1a23 content_type: application/pdf creator: dernst date_created: 2023-07-19T06:55:39Z date_updated: 2023-07-19T06:55:39Z file_id: '13253' file_name: 2023_JourPhysChemistry_Wei.pdf file_size: 2121252 relation: main_file success: 1 file_date_updated: 2023-07-19T06:55:39Z has_accepted_license: '1' intvolume: ' 14' isi: 1 issue: '27' keyword: - General Materials Science - Physical and Theoretical Chemistry language: - iso: eng month: '07' oa: 1 oa_version: Published Version page: 6309-6314 project: - _id: 2688CF98-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '801770' name: 'Angulon: physics and applications of a new quasiparticle' publication: The Journal of Physical Chemistry Letters publication_identifier: eissn: - 1948-7185 publication_status: published publisher: American Chemical Society quality_controlled: '1' status: public title: Bond polarizability as a probe of local crystal fields in hybrid lead-halide perovskites 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: 14 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: '14342' abstract: - lang: eng text: We propose a simple method to measure nonlinear Kerr refractive index in mid-infrared frequency range that avoids using sophisticated infrared detectors. Our approach is based on using a near-infrared probe beam which interacts with a mid-IR beam via wavelength-non-degenerate cross-phase modulation (XPM). By carefully measuring XPM-induced spectral modifications in the probe beam and comparing the experimental data with simulation results, we extract the value for the non-degenerate Kerr index. Finally, in order to obtain the value of degenerate mid-IR Kerr index, we use the well-established two-band formalism of Sheik-Bahae et al., which is shown to become particularly simple in the limit of low frequencies. The proposed technique is complementary to the conventional techniques, such as z-scan, and has the advantage of not requiring any mid-infrared detectors. acknowledgement: The work was supported by IST Austria. The authors would like to gratefully acknowledge the help and assistance of Professor John M. Dudley. article_number: '091104' article_processing_charge: Yes (in subscription journal) article_type: original author: - first_name: Dusan full_name: Lorenc, Dusan id: 40D8A3E6-F248-11E8-B48F-1D18A9856A87 last_name: Lorenc - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 citation: ama: Lorenc D, Alpichshev Z. Mid-infrared Kerr index evaluation via cross-phase modulation with a near-infrared probe beam. Applied Physics Letters. 2023;123(9). doi:10.1063/5.0161713 apa: Lorenc, D., & Alpichshev, Z. (2023). Mid-infrared Kerr index evaluation via cross-phase modulation with a near-infrared probe beam. Applied Physics Letters. AIP Publishing. https://doi.org/10.1063/5.0161713 chicago: Lorenc, Dusan, and Zhanybek Alpichshev. “Mid-Infrared Kerr Index Evaluation via Cross-Phase Modulation with a near-Infrared Probe Beam.” Applied Physics Letters. AIP Publishing, 2023. https://doi.org/10.1063/5.0161713. ieee: D. Lorenc and Z. Alpichshev, “Mid-infrared Kerr index evaluation via cross-phase modulation with a near-infrared probe beam,” Applied Physics Letters, vol. 123, no. 9. AIP Publishing, 2023. ista: Lorenc D, Alpichshev Z. 2023. Mid-infrared Kerr index evaluation via cross-phase modulation with a near-infrared probe beam. Applied Physics Letters. 123(9), 091104. mla: Lorenc, Dusan, and Zhanybek Alpichshev. “Mid-Infrared Kerr Index Evaluation via Cross-Phase Modulation with a near-Infrared Probe Beam.” Applied Physics Letters, vol. 123, no. 9, 091104, AIP Publishing, 2023, doi:10.1063/5.0161713. short: D. Lorenc, Z. Alpichshev, Applied Physics Letters 123 (2023). date_created: 2023-09-17T22:01:09Z date_published: 2023-08-28T00:00:00Z date_updated: 2023-09-20T11:50:06Z day: '28' ddc: - '530' department: - _id: ZhAl doi: 10.1063/5.0161713 external_id: arxiv: - '2306.09043' file: - access_level: open_access checksum: 89a1b604d58b209fec66c6b6f919ac98 content_type: application/pdf creator: dernst date_created: 2023-09-20T11:36:16Z date_updated: 2023-09-20T11:36:16Z file_id: '14353' file_name: 2023_ApplPhysLetter_Lorenc.pdf file_size: 1486715 relation: main_file success: 1 file_date_updated: 2023-09-20T11:36:16Z has_accepted_license: '1' intvolume: ' 123' issue: '9' language: - iso: eng month: '08' oa: 1 oa_version: Published Version publication: Applied Physics Letters publication_identifier: issn: - 0003-6951 publication_status: published publisher: AIP Publishing quality_controlled: '1' scopus_import: '1' status: public title: Mid-infrared Kerr index evaluation via cross-phase modulation with a near-infrared probe beam 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: 123 year: '2023' ... --- _id: '11737' abstract: - lang: eng text: Spin-orbit coupling in thin HgTe quantum wells results in a relativistic-like electron band structure, making it a versatile solid state platform to observe and control nontrivial electrodynamic phenomena. Here we report an observation of universal terahertz (THz) transparency determined by fine-structure constant α≈1/137 in 6.5-nm-thick HgTe layer, close to the critical thickness separating phases with topologically different electronic band structure. Using THz spectroscopy in a magnetic field we obtain direct evidence of asymmetric spin splitting of the Dirac cone. This particle-hole asymmetry facilitates optical control of edge spin currents in the quantum wells. acknowledgement: This work was supported by the Austrian Science Funds (W 1243, I 3456-N27, I 5539-N). article_number: '045302' article_processing_charge: No article_type: original author: - first_name: Uladzislau full_name: Dziom, Uladzislau id: 6A9A37C2-8C5C-11E9-AE53-F2FDE5697425 last_name: Dziom orcid: 0000-0002-1648-0999 - first_name: A. full_name: Shuvaev, A. last_name: Shuvaev - first_name: J. full_name: Gospodarič, J. last_name: Gospodarič - first_name: E. G. full_name: Novik, E. G. last_name: Novik - first_name: A. A. full_name: Dobretsova, A. A. last_name: Dobretsova - first_name: N. N. full_name: Mikhailov, N. N. last_name: Mikhailov - first_name: Z. D. full_name: Kvon, Z. D. last_name: Kvon - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: A. full_name: Pimenov, A. last_name: Pimenov citation: ama: Dziom U, Shuvaev A, Gospodarič J, et al. Universal transparency and asymmetric spin splitting near the Dirac point in HgTe quantum wells. Physical Review B. 2022;106(4). doi:10.1103/PhysRevB.106.045302 apa: Dziom, U., Shuvaev, A., Gospodarič, J., Novik, E. G., Dobretsova, A. A., Mikhailov, N. N., … Pimenov, A. (2022). Universal transparency and asymmetric spin splitting near the Dirac point in HgTe quantum wells. Physical Review B. American Physical Society. https://doi.org/10.1103/PhysRevB.106.045302 chicago: Dziom, Uladzislau, A. Shuvaev, J. Gospodarič, E. G. Novik, A. A. Dobretsova, N. N. Mikhailov, Z. D. Kvon, Zhanybek Alpichshev, and A. Pimenov. “Universal Transparency and Asymmetric Spin Splitting near the Dirac Point in HgTe Quantum Wells.” Physical Review B. American Physical Society, 2022. https://doi.org/10.1103/PhysRevB.106.045302. ieee: U. Dziom et al., “Universal transparency and asymmetric spin splitting near the Dirac point in HgTe quantum wells,” Physical Review B, vol. 106, no. 4. American Physical Society, 2022. ista: Dziom U, Shuvaev A, Gospodarič J, Novik EG, Dobretsova AA, Mikhailov NN, Kvon ZD, Alpichshev Z, Pimenov A. 2022. Universal transparency and asymmetric spin splitting near the Dirac point in HgTe quantum wells. Physical Review B. 106(4), 045302. mla: Dziom, Uladzislau, et al. “Universal Transparency and Asymmetric Spin Splitting near the Dirac Point in HgTe Quantum Wells.” Physical Review B, vol. 106, no. 4, 045302, American Physical Society, 2022, doi:10.1103/PhysRevB.106.045302. short: U. Dziom, A. Shuvaev, J. Gospodarič, E.G. Novik, A.A. Dobretsova, N.N. Mikhailov, Z.D. Kvon, Z. Alpichshev, A. Pimenov, Physical Review B 106 (2022). date_created: 2022-08-07T22:01:58Z date_published: 2022-07-15T00:00:00Z date_updated: 2023-08-03T12:38:57Z day: '15' ddc: - '530' department: - _id: ZhAl doi: 10.1103/PhysRevB.106.045302 external_id: isi: - '000834349200010' file: - access_level: open_access checksum: 115aff9e0cde2f806cb26953d7262791 content_type: application/pdf creator: dernst date_created: 2022-08-08T06:58:22Z date_updated: 2022-08-08T06:58:22Z file_id: '11743' file_name: 2022_PhysRevB_Dziom.pdf file_size: 774455 relation: main_file success: 1 file_date_updated: 2022-08-08T06:58:22Z has_accepted_license: '1' intvolume: ' 106' isi: 1 issue: '4' language: - iso: eng month: '07' oa: 1 oa_version: Published Version 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: Universal transparency and asymmetric spin splitting near the Dirac point in HgTe quantum wells 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: 106 year: '2022' ... --- _id: '394' abstract: - lang: eng text: 'The valley pseudospin in monolayer transition metal dichalcogenides (TMDs) has been proposed as a new way to manipulate information in various optoelectronic devices. This relies on a large valley polarization that remains stable over long time scales (hundreds of nanoseconds). However, time-resolved measurements report valley lifetimes of only a few picoseconds. This has been attributed to mechanisms such as phonon-mediated intervalley scattering and a precession of the valley pseudospin through electron-hole exchange. Here we use transient spin grating to directly measure the valley depolarization lifetime in monolayer MoSe2. We find a fast valley decay rate that scales linearly with the excitation density at different temperatures. This establishes the presence of strong exciton-exciton Coulomb exchange interactions enhancing the valley depolarization. Our work highlights the microscopic processes inhibiting the efficient use of the exciton valley pseudospin in monolayer TMDs. ' author: - first_name: Fahad full_name: Mahmood, Fahad last_name: Mahmood - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Yi full_name: Lee, Yi last_name: Lee - first_name: Jing full_name: Kong, Jing last_name: Kong - first_name: Nuh full_name: Gedik, Nuh last_name: Gedik citation: ama: Mahmood F, Alpichshev Z, Lee Y, Kong J, Gedik N. Observation of exciton-exciton interaction mediated valley Depolarization in Monolayer MoSe2. Nano Letters. 2018;18(1):223-228. doi:10.1021/acs.nanolett.7b03953 apa: Mahmood, F., Alpichshev, Z., Lee, Y., Kong, J., & Gedik, N. (2018). Observation of exciton-exciton interaction mediated valley Depolarization in Monolayer MoSe2. Nano Letters. American Chemical Society. https://doi.org/10.1021/acs.nanolett.7b03953 chicago: Mahmood, Fahad, Zhanybek Alpichshev, Yi Lee, Jing Kong, and Nuh Gedik. “Observation of Exciton-Exciton Interaction Mediated Valley Depolarization in Monolayer MoSe2.” Nano Letters. American Chemical Society, 2018. https://doi.org/10.1021/acs.nanolett.7b03953. ieee: F. Mahmood, Z. Alpichshev, Y. Lee, J. Kong, and N. Gedik, “Observation of exciton-exciton interaction mediated valley Depolarization in Monolayer MoSe2,” Nano Letters, vol. 18, no. 1. American Chemical Society, pp. 223–228, 2018. ista: Mahmood F, Alpichshev Z, Lee Y, Kong J, Gedik N. 2018. Observation of exciton-exciton interaction mediated valley Depolarization in Monolayer MoSe2. Nano Letters. 18(1), 223–228. mla: Mahmood, Fahad, et al. “Observation of Exciton-Exciton Interaction Mediated Valley Depolarization in Monolayer MoSe2.” Nano Letters, vol. 18, no. 1, American Chemical Society, 2018, pp. 223–28, doi:10.1021/acs.nanolett.7b03953. short: F. Mahmood, Z. Alpichshev, Y. Lee, J. Kong, N. Gedik, Nano Letters 18 (2018) 223–228. date_created: 2018-12-11T11:46:13Z date_published: 2018-01-10T00:00:00Z date_updated: 2021-01-12T07:53:20Z day: '10' doi: 10.1021/acs.nanolett.7b03953 extern: '1' external_id: arxiv: - '1712.07925' intvolume: ' 18' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1712.07925 month: '01' oa: 1 oa_version: Submitted Version page: 223 - 228 publication: Nano Letters publication_status: published publisher: American Chemical Society publist_id: '7435' quality_controlled: '1' status: public title: Observation of exciton-exciton interaction mediated valley Depolarization in Monolayer MoSe2 type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 18 year: '2018' ... --- _id: '391' abstract: - lang: eng text: 'Three-dimensional topological insulators are bulk insulators with Z 2 topological electronic order that gives rise to conducting light-like surface states. These surface electrons are exceptionally resistant to localization by non-magnetic disorder, and have been adopted as the basis for a wide range of proposals to achieve new quasiparticle species and device functionality. Recent studies have yielded a surprise by showing that in spite of resisting localization, topological insulator surface electrons can be reshaped by defects into distinctive resonance states. Here we use numerical simulations and scanning tunnelling microscopy data to show that these resonance states have significance well beyond the localized regime usually associated with impurity bands. At native densities in the model Bi2X3 (X=Bi, Te) compounds, defect resonance states are predicted to generate a new quantum basis for an emergent electron gas that supports diffusive electrical transport. ' author: - first_name: Yishuai full_name: Xu, Yishuai last_name: Xu - first_name: Janet full_name: Chiu, Janet last_name: Chiu - first_name: Lin full_name: Miao, Lin last_name: Miao - first_name: Haowei full_name: He, Haowei last_name: He - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Aharon full_name: Kapitulnik, Aharon last_name: Kapitulnik - first_name: Rudro full_name: Biswas, Rudro last_name: Biswas - first_name: Lewis full_name: Wray, Lewis last_name: Wray citation: ama: Xu Y, Chiu J, Miao L, et al. Disorder enabled band structure engineering of a topological insulator surface. Nature Communications. 2017;8. doi:10.1038/ncomms14081 apa: Xu, Y., Chiu, J., Miao, L., He, H., Alpichshev, Z., Kapitulnik, A., … Wray, L. (2017). Disorder enabled band structure engineering of a topological insulator surface. Nature Communications. Nature Publishing Group. https://doi.org/10.1038/ncomms14081 chicago: Xu, Yishuai, Janet Chiu, Lin Miao, Haowei He, Zhanybek Alpichshev, Aharon Kapitulnik, Rudro Biswas, and Lewis Wray. “Disorder Enabled Band Structure Engineering of a Topological Insulator Surface.” Nature Communications. Nature Publishing Group, 2017. https://doi.org/10.1038/ncomms14081. ieee: Y. Xu et al., “Disorder enabled band structure engineering of a topological insulator surface,” Nature Communications, vol. 8. Nature Publishing Group, 2017. ista: Xu Y, Chiu J, Miao L, He H, Alpichshev Z, Kapitulnik A, Biswas R, Wray L. 2017. Disorder enabled band structure engineering of a topological insulator surface. Nature Communications. 8. mla: Xu, Yishuai, et al. “Disorder Enabled Band Structure Engineering of a Topological Insulator Surface.” Nature Communications, vol. 8, Nature Publishing Group, 2017, doi:10.1038/ncomms14081. short: Y. Xu, J. Chiu, L. Miao, H. He, Z. Alpichshev, A. Kapitulnik, R. Biswas, L. Wray, Nature Communications 8 (2017). date_created: 2018-12-11T11:46:12Z date_published: 2017-02-03T00:00:00Z date_updated: 2021-01-12T07:53:08Z day: '03' doi: 10.1038/ncomms14081 extern: '1' intvolume: ' 8' language: - iso: eng month: '02' oa_version: None publication: Nature Communications publication_status: published publisher: Nature Publishing Group publist_id: '7438' status: public title: Disorder enabled band structure engineering of a topological insulator surface type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 8 year: '2017' ... --- _id: '393' abstract: - lang: eng text: 'We use a three-pulse ultrafast optical spectroscopy to study the relaxation processes in a frustrated Mott insulator Na2IrO3. By being able to independently produce the out-of-equilibrium bound states (excitons) of doublons and holons with the first pulse and suppress the underlying antiferromagnetic order with the second one, we were able to elucidate the relaxation mechanism of quasiparticles in this system. By observing the difference in the exciton dynamics in the magnetically ordered and disordered phases we found that the mass of this quasiparticle is mostly determined by its interaction with the surrounding spins. ' acknowledgement: "Z.A. gratefully acknowledges discussions with P. A. Lee and A. Kemper. A conversation with J. Zaanen was instrumental in clarifying the physical picture described in this paper. We would also like to thank A. Kogar for thoroughly reading the manuscript and making valuable comments. This work was supported by Army Research Office Grant No. W911NF-15-1-0128 and Gordon and Betty Moore Foundation EPiQS Initiative through Grant No. GBMF4540 (time resolved optical spectroscopy), Skoltech, as part of the Skoltech NGP program (theory) and National Science Foundation Grant No. DMR-1265162 (material growth).\r\n\r\n" author: - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Edbert full_name: Sie, Edbert last_name: Sie - first_name: Fahad full_name: Mahmood, Fahad last_name: Mahmood - first_name: Gang full_name: Cao, Gang last_name: Cao - first_name: Nuh full_name: Gedik, Nuh last_name: Gedik citation: ama: Alpichshev Z, Sie E, Mahmood F, Cao G, Gedik N. Origin of the exciton mass in the frustrated Mott insulator Na2IrO3. Physical Review B. 2017;96(23). doi:10.1103/PhysRevB.96.235141 apa: Alpichshev, Z., Sie, E., Mahmood, F., Cao, G., & Gedik, N. (2017). Origin of the exciton mass in the frustrated Mott insulator Na2IrO3. Physical Review B. American Physical Society. https://doi.org/10.1103/PhysRevB.96.235141 chicago: Alpichshev, Zhanybek, Edbert Sie, Fahad Mahmood, Gang Cao, and Nuh Gedik. “Origin of the Exciton Mass in the Frustrated Mott Insulator Na2IrO3.” Physical Review B. American Physical Society, 2017. https://doi.org/10.1103/PhysRevB.96.235141. ieee: Z. Alpichshev, E. Sie, F. Mahmood, G. Cao, and N. Gedik, “Origin of the exciton mass in the frustrated Mott insulator Na2IrO3,” Physical Review B, vol. 96, no. 23. American Physical Society, 2017. ista: Alpichshev Z, Sie E, Mahmood F, Cao G, Gedik N. 2017. Origin of the exciton mass in the frustrated Mott insulator Na2IrO3. Physical Review B. 96(23). mla: Alpichshev, Zhanybek, et al. “Origin of the Exciton Mass in the Frustrated Mott Insulator Na2IrO3.” Physical Review B, vol. 96, no. 23, American Physical Society, 2017, doi:10.1103/PhysRevB.96.235141. short: Z. Alpichshev, E. Sie, F. Mahmood, G. Cao, N. Gedik, Physical Review B 96 (2017). date_created: 2018-12-11T11:46:13Z date_published: 2017-12-26T00:00:00Z date_updated: 2021-01-12T07:53:16Z day: '26' doi: 10.1103/PhysRevB.96.235141 extern: '1' intvolume: ' 96' issue: '23' language: - iso: eng main_file_link: - open_access: '1' url: http://dspace.mit.edu/handle/1721.1/114259 month: '12' oa: 1 oa_version: None publication: Physical Review B publication_status: published publisher: American Physical Society publist_id: '7436' status: public title: Origin of the exciton mass in the frustrated Mott insulator Na2IrO3 type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 96 year: '2017' ... --- _id: '392' abstract: - lang: eng text: We used femtosecond optical pump-probe spectroscopy to study the photoinduced change in reflectivity of thin films of the electron-doped cuprate La2-xCexCuO4 (LCCO) with dopings of x=0.08 (underdoped) and x=0.11 (optimally doped). Above Tc, we observe fluence-dependent relaxation rates that begin at a temperature similar to the one where transport measurements first show signatures of antiferromagnetic correlations. Upon suppressing superconductivity with a magnetic field, it is found that the fluence and temperature dependence of relaxation rates are consistent with bimolecular recombination of electrons and holes across a gap (2ΔAF) originating from antiferromagnetic correlations which comprise the pseudogap in electron-doped cuprates. This can be used to learn about coupling between electrons and high-energy (ω>2ΔAF) excitations in these compounds and set limits on the time scales on which antiferromagnetic correlations are static. acknowledgement: Optical pump-probe work was supported by the Gordon and Betty Moore Foundation's EPiQS initiative through Grant No. GBMF4540. Materials growth and characterization was supported by AFOSR FA95501410332 and NSF DMR1410665. author: - first_name: Inna full_name: Vishik, Inna last_name: Vishik - first_name: Fahad full_name: Mahmood, Fahad last_name: Mahmood - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Nuh full_name: Gedik, Nuh last_name: Gedik - first_name: Joshu full_name: Higgins, Joshu last_name: Higgins - first_name: Richard full_name: Greene, Richard last_name: Greene citation: ama: Vishik I, Mahmood F, Alpichshev Z, Gedik N, Higgins J, Greene R. Ultrafast dynamics in the presence of antiferromagnetic correlations in electron doped cuprate La2 xCexCuO4±δ. Physical Review B. 2017;95(11). doi:10.1103/PhysRevB.95.115125 apa: Vishik, I., Mahmood, F., Alpichshev, Z., Gedik, N., Higgins, J., & Greene, R. (2017). Ultrafast dynamics in the presence of antiferromagnetic correlations in electron doped cuprate La2 xCexCuO4±δ. Physical Review B. American Physical Society. https://doi.org/10.1103/PhysRevB.95.115125 chicago: Vishik, Inna, Fahad Mahmood, Zhanybek Alpichshev, Nuh Gedik, Joshu Higgins, and Richard Greene. “Ultrafast Dynamics in the Presence of Antiferromagnetic Correlations in Electron Doped Cuprate La2 XCexCuO4±δ.” Physical Review B. American Physical Society, 2017. https://doi.org/10.1103/PhysRevB.95.115125. ieee: I. Vishik, F. Mahmood, Z. Alpichshev, N. Gedik, J. Higgins, and R. Greene, “Ultrafast dynamics in the presence of antiferromagnetic correlations in electron doped cuprate La2 xCexCuO4±δ,” Physical Review B, vol. 95, no. 11. American Physical Society, 2017. ista: Vishik I, Mahmood F, Alpichshev Z, Gedik N, Higgins J, Greene R. 2017. Ultrafast dynamics in the presence of antiferromagnetic correlations in electron doped cuprate La2 xCexCuO4±δ. Physical Review B. 95(11). mla: Vishik, Inna, et al. “Ultrafast Dynamics in the Presence of Antiferromagnetic Correlations in Electron Doped Cuprate La2 XCexCuO4±δ.” Physical Review B, vol. 95, no. 11, American Physical Society, 2017, doi:10.1103/PhysRevB.95.115125. short: I. Vishik, F. Mahmood, Z. Alpichshev, N. Gedik, J. Higgins, R. Greene, Physical Review B 95 (2017). date_created: 2018-12-11T11:46:13Z date_published: 2017-03-13T00:00:00Z date_updated: 2021-01-12T07:53:12Z day: '13' doi: 10.1103/PhysRevB.95.115125 extern: '1' intvolume: ' 95' issue: '11' language: - iso: eng main_file_link: - open_access: '1' url: http://dspace.mit.edu/handle/1721.1/109835 month: '03' oa: 1 oa_version: None publication: Physical Review B publication_status: published publisher: American Physical Society publist_id: '7437' status: public title: Ultrafast dynamics in the presence of antiferromagnetic correlations in electron doped cuprate La2 xCexCuO4±δ type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 95 year: '2017' ... --- _id: '390' abstract: - lang: eng text: In the underdoped copper-oxides, high-temperature superconductivity condenses from a nonconventional metallic "pseudogap" phase that exhibits a variety of non-Fermi liquid properties. Recently, it has become clear that a charge density wave (CDW) phase exists within the pseudogap regime. This CDW coexists and competes with superconductivity (SC) below the transition temperature Tc, suggesting that these two orders are intimately related. Here we show that the condensation of the superfluid from this unconventional precursor is reflected in deviations from the predictions of BSC theory regarding the recombination rate of quasiparticles. We report a detailed investigation of the quasiparticle (QP) recombination lifetime, τqp, as a function of temperature and magnetic field in underdoped HgBa2CuO4+δ (Hg-1201) and YBa2Cu3O6+x (YBCO) single crystals by ultrafast time-resolved reflectivity. We find that τqp (T) exhibits a local maximum in a small temperature window near Tc that is prominent in underdoped samples with coexisting charge order and vanishes with application of a small magnetic field. We explain this unusual, non-BCS behavior by positing that Tc marks a transition from phase-fluctuating SC/CDW composite order above to a SC/CDW condensate below. Our results suggest that the superfluid in underdoped cuprates is a condensate of coherently-mixed particle-particle and particle-hole pairs. author: - first_name: James full_name: Hinton, James last_name: Hinton - first_name: E full_name: Thewalt, E last_name: Thewalt - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Fahad full_name: Mahmood, Fahad last_name: Mahmood - first_name: Jake full_name: Koralek, Jake last_name: Koralek - first_name: Mun full_name: Chan, Mun last_name: Chan - first_name: Michael full_name: Veit, Michael last_name: Veit - first_name: Chelsey full_name: Dorow, Chelsey last_name: Dorow - first_name: Neven full_name: Barišić, Neven last_name: Barišić - first_name: Alexander full_name: Kemper, Alexander last_name: Kemper - first_name: Doug full_name: Bonn, Doug last_name: Bonn - first_name: Walter full_name: Hardy, Walter last_name: Hardy - first_name: Ruixing full_name: Liang, Ruixing last_name: Liang - first_name: Nuh full_name: Gedik, Nuh last_name: Gedik - first_name: Martin full_name: Greven, Martin last_name: Greven - first_name: Alessandra full_name: Lanzara, Alessandra last_name: Lanzara - first_name: Joseph full_name: Orenstein, Joseph last_name: Orenstein citation: ama: Hinton J, Thewalt E, Alpichshev Z, et al. The rate of quasiparticle recombination probes the onset of coherence in cuprate superconductors. Scientific Reports. 2016;6. doi:10.1038/srep23610 apa: Hinton, J., Thewalt, E., Alpichshev, Z., Mahmood, F., Koralek, J., Chan, M., … Orenstein, J. (2016). The rate of quasiparticle recombination probes the onset of coherence in cuprate superconductors. Scientific Reports. Nature Publishing Group. https://doi.org/10.1038/srep23610 chicago: Hinton, James, E Thewalt, Zhanybek Alpichshev, Fahad Mahmood, Jake Koralek, Mun Chan, Michael Veit, et al. “The Rate of Quasiparticle Recombination Probes the Onset of Coherence in Cuprate Superconductors.” Scientific Reports. Nature Publishing Group, 2016. https://doi.org/10.1038/srep23610. ieee: J. Hinton et al., “The rate of quasiparticle recombination probes the onset of coherence in cuprate superconductors,” Scientific Reports, vol. 6. Nature Publishing Group, 2016. ista: Hinton J, Thewalt E, Alpichshev Z, Mahmood F, Koralek J, Chan M, Veit M, Dorow C, Barišić N, Kemper A, Bonn D, Hardy W, Liang R, Gedik N, Greven M, Lanzara A, Orenstein J. 2016. The rate of quasiparticle recombination probes the onset of coherence in cuprate superconductors. Scientific Reports. 6. mla: Hinton, James, et al. “The Rate of Quasiparticle Recombination Probes the Onset of Coherence in Cuprate Superconductors.” Scientific Reports, vol. 6, Nature Publishing Group, 2016, doi:10.1038/srep23610. short: J. Hinton, E. Thewalt, Z. Alpichshev, F. Mahmood, J. Koralek, M. Chan, M. Veit, C. Dorow, N. Barišić, A. Kemper, D. Bonn, W. Hardy, R. Liang, N. Gedik, M. Greven, A. Lanzara, J. Orenstein, Scientific Reports 6 (2016). date_created: 2018-12-11T11:46:12Z date_published: 2016-04-13T00:00:00Z date_updated: 2021-01-12T07:53:03Z day: '13' doi: 10.1038/srep23610 extern: '1' intvolume: ' 6' language: - iso: eng month: '04' oa_version: None publication: Scientific Reports publication_status: published publisher: Nature Publishing Group publist_id: '7439' status: public title: The rate of quasiparticle recombination probes the onset of coherence in cuprate superconductors type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 6 year: '2016' ... --- _id: '389' abstract: - lang: eng text: The coherent optical manipulation of solids is emerging as a promising way to engineer novel quantum states of matter. The strong time-periodic potential of intense laser light can be used to generate hybrid photon-electron states. Interaction of light with Bloch states leads to Floquet-Bloch states, which are essential in realizing new photo-induced quantum phases. Similarly, dressing of free-electron states near the surface of a solid generates Volkov states, which are used to study nonlinear optics in atoms and semiconductors. The interaction of these two dynamic states with each other remains an open experimental problem. Here we use time- and angle-resolved photoemission spectroscopy (Tr-ARPES) to selectively study the transition between these two states on the surface of the topological insulator Bi2Se3. We find that the coupling between the two strongly depends on the electron momentum, providing a route to enhance or inhibit it. Moreover, by controlling the light polarization we can negate Volkov states to generate pure Floquet-Bloch states. This work establishes a systematic path for the coherent manipulation of solids via light-matter interaction. acknowledgement: The authors would like to thank C. Lee for useful discussions. This work is supported by US Department of Energy (DOE), Basic Energy Sciences, Division of Materials Sciences and Engineering (experimental set-up, data acquisition and theory), Army Research Office (electron spectrometer) and by the Gordon and Betty Moore Foundation’s EPiQS Initiative through Grant GBMF4540 (data analysis). author: - first_name: Fahad full_name: Mahmood, Fahad last_name: Mahmood - first_name: Ching full_name: Chan, Ching last_name: Chan - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Dillon full_name: Gardner, Dillon last_name: Gardner - first_name: Young full_name: Lee, Young last_name: Lee - first_name: Patrick full_name: Lee, Patrick last_name: Lee - first_name: Nuh full_name: Gedik, Nuh last_name: Gedik citation: ama: Mahmood F, Chan C, Alpichshev Z, et al. Selective scattering between Floquet Bloch and Volkov states in a topological insulator. Nature Physics. 2016;12(4):306-310. doi:10.1038/nphys3609 apa: Mahmood, F., Chan, C., Alpichshev, Z., Gardner, D., Lee, Y., Lee, P., & Gedik, N. (2016). Selective scattering between Floquet Bloch and Volkov states in a topological insulator. Nature Physics. Nature Publishing Group. https://doi.org/10.1038/nphys3609 chicago: Mahmood, Fahad, Ching Chan, Zhanybek Alpichshev, Dillon Gardner, Young Lee, Patrick Lee, and Nuh Gedik. “Selective Scattering between Floquet Bloch and Volkov States in a Topological Insulator.” Nature Physics. Nature Publishing Group, 2016. https://doi.org/10.1038/nphys3609. ieee: F. Mahmood et al., “Selective scattering between Floquet Bloch and Volkov states in a topological insulator,” Nature Physics, vol. 12, no. 4. Nature Publishing Group, pp. 306–310, 2016. ista: Mahmood F, Chan C, Alpichshev Z, Gardner D, Lee Y, Lee P, Gedik N. 2016. Selective scattering between Floquet Bloch and Volkov states in a topological insulator. Nature Physics. 12(4), 306–310. mla: Mahmood, Fahad, et al. “Selective Scattering between Floquet Bloch and Volkov States in a Topological Insulator.” Nature Physics, vol. 12, no. 4, Nature Publishing Group, 2016, pp. 306–10, doi:10.1038/nphys3609. short: F. Mahmood, C. Chan, Z. Alpichshev, D. Gardner, Y. Lee, P. Lee, N. Gedik, Nature Physics 12 (2016) 306–310. date_created: 2018-12-11T11:46:11Z date_published: 2016-04-01T00:00:00Z date_updated: 2021-01-12T07:52:59Z day: '01' doi: 10.1038/nphys3609 extern: '1' intvolume: ' 12' issue: '4' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1512.05714 month: '04' oa: 1 oa_version: None page: 306 - 310 publication: Nature Physics publication_status: published publisher: Nature Publishing Group publist_id: '7440' status: public title: Selective scattering between Floquet Bloch and Volkov states in a topological insulator type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 12 year: '2016' ... --- _id: '388' abstract: - lang: eng text: We use ultrafast optical spectroscopy to observe binding of charged single-particle excitations (SE) in the magnetically frustrated Mott insulator Na2IrO3. Above the antiferromagnetic ordering temperature (TN) the system response is due to both Hubbard excitons (HE) and their constituent unpaired SE. The SE response becomes strongly suppressed immediately below TN. We argue that this increase in binding energy is due to a unique interplay between the frustrated Kitaev and the weak Heisenberg-type ordering term in the Hamiltonian, mediating an effective interaction between the spin-singlet SE. This interaction grows with distance causing the SE to become trapped in the HE, similar to quark confinement inside hadrons. This binding of charged particles, induced by magnetic ordering, is a result of a confinement-deconfinement transition of spin excitations. This observation provides evidence for spin liquid type behavior which is expected in Na2IrO3. article_processing_charge: No article_type: original author: - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Fahad full_name: Mahmood, Fahad last_name: Mahmood - first_name: Gang full_name: Cao, Gang last_name: Cao - first_name: Nuh full_name: Gedik, Nuh last_name: Gedik citation: ama: Alpichshev Z, Mahmood F, Cao G, Gedik N. Confinement deconfinement transition as an indication of spin liquid type behavior in Na2IrO3. Physical Review Letters. 2015;114(1). doi:10.1103/PhysRevLett.114.017203 apa: Alpichshev, Z., Mahmood, F., Cao, G., & Gedik, N. (2015). Confinement deconfinement transition as an indication of spin liquid type behavior in Na2IrO3. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.114.017203 chicago: Alpichshev, Zhanybek, Fahad Mahmood, Gang Cao, and Nuh Gedik. “Confinement Deconfinement Transition as an Indication of Spin Liquid Type Behavior in Na2IrO3.” Physical Review Letters. American Physical Society, 2015. https://doi.org/10.1103/PhysRevLett.114.017203. ieee: Z. Alpichshev, F. Mahmood, G. Cao, and N. Gedik, “Confinement deconfinement transition as an indication of spin liquid type behavior in Na2IrO3,” Physical Review Letters, vol. 114, no. 1. American Physical Society, 2015. ista: Alpichshev Z, Mahmood F, Cao G, Gedik N. 2015. Confinement deconfinement transition as an indication of spin liquid type behavior in Na2IrO3. Physical Review Letters. 114(1). mla: Alpichshev, Zhanybek, et al. “Confinement Deconfinement Transition as an Indication of Spin Liquid Type Behavior in Na2IrO3.” Physical Review Letters, vol. 114, no. 1, American Physical Society, 2015, doi:10.1103/PhysRevLett.114.017203. short: Z. Alpichshev, F. Mahmood, G. Cao, N. Gedik, Physical Review Letters 114 (2015). date_created: 2018-12-11T11:46:11Z date_published: 2015-07-07T00:00:00Z date_updated: 2021-01-12T07:52:54Z day: '07' doi: 10.1103/PhysRevLett.114.017203 extern: '1' intvolume: ' 114' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://dspace.mit.edu/handle/1721.1/92979 month: '07' oa: 1 oa_version: Published Version publication: Physical Review Letters publication_status: published publisher: American Physical Society publist_id: '7441' quality_controlled: '1' status: public title: Confinement deconfinement transition as an indication of spin liquid type behavior in Na2IrO3 type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 114 year: '2015' ... --- _id: '387' abstract: - lang: eng text: In this Letter we present detailed study of the density of states near defects in Bi 2Se 3. In particular, we present data on the commonly found triangular defects in this system. While we do not find any measurable quasiparticle scattering interference effects, we do find localized resonances, which can be well fitted by theory once the potential is taken to be extended to properly account for the observed defects. The data together with the fits confirm that while the local density of states around the Dirac point of the electronic spectrum at the surface is significantly disrupted near the impurity by the creation of low-energy resonance state, the Dirac point is not locally destroyed. We discuss our results in terms of the expected protected surface state of topological insulators. © 2012 American Physical Society. author: - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Rudro full_name: Biswas, Rudro last_name: Biswas - first_name: Alexander full_name: Balatsky, Alexander last_name: Balatsky - first_name: James full_name: Analytis, James last_name: Analytis - first_name: Jiunhaw full_name: Chu, Jiunhaw last_name: Chu - first_name: Ian full_name: Fisher, Ian last_name: Fisher - first_name: Aharon full_name: Kapitulnik, Aharon last_name: Kapitulnik citation: ama: Alpichshev Z, Biswas R, Balatsky A, et al. STM imaging of impurity resonances on Bi 2Se 3. Physical Review Letters. 2012;108(20). doi:10.1103/PhysRevLett.108.206402 apa: Alpichshev, Z., Biswas, R., Balatsky, A., Analytis, J., Chu, J., Fisher, I., & Kapitulnik, A. (2012). STM imaging of impurity resonances on Bi 2Se 3. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.108.206402 chicago: Alpichshev, Zhanybek, Rudro Biswas, Alexander Balatsky, James Analytis, Jiunhaw Chu, Ian Fisher, and Aharon Kapitulnik. “STM Imaging of Impurity Resonances on Bi 2Se 3.” Physical Review Letters. American Physical Society, 2012. https://doi.org/10.1103/PhysRevLett.108.206402. ieee: Z. Alpichshev et al., “STM imaging of impurity resonances on Bi 2Se 3,” Physical Review Letters, vol. 108, no. 20. American Physical Society, 2012. ista: Alpichshev Z, Biswas R, Balatsky A, Analytis J, Chu J, Fisher I, Kapitulnik A. 2012. STM imaging of impurity resonances on Bi 2Se 3. Physical Review Letters. 108(20). mla: Alpichshev, Zhanybek, et al. “STM Imaging of Impurity Resonances on Bi 2Se 3.” Physical Review Letters, vol. 108, no. 20, American Physical Society, 2012, doi:10.1103/PhysRevLett.108.206402. short: Z. Alpichshev, R. Biswas, A. Balatsky, J. Analytis, J. Chu, I. Fisher, A. Kapitulnik, Physical Review Letters 108 (2012). date_created: 2018-12-11T11:46:11Z date_published: 2012-01-01T00:00:00Z date_updated: 2021-01-12T07:52:49Z day: '01' doi: 10.1103/PhysRevLett.108.206402 extern: '1' intvolume: ' 108' issue: '20' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1108.0022 month: '01' oa: 1 oa_version: None publication: Physical Review Letters publication_status: published publisher: American Physical Society publist_id: '7442' status: public title: STM imaging of impurity resonances on Bi 2Se 3 type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 108 year: '2012' ... --- _id: '386' abstract: - lang: eng text: 'We present a detailed study of the local density of states (LDOS) associated with the surface-state band near a step edge of the strong topological insulator Bi2Te3 and reveal a one-dimensional bound state that runs parallel to the step edge and is bound to it at some characteristic distance. This bound state is clearly observed in the bulk gap region, while it becomes entangled with the oscillations of the warped surface band at high energy, and with the valence-band states near the Dirac point. We obtain excellent fits to theoretical predictions [Alpichshev, 2011] that properly incorporate the three-dimensional nature of the problem to the surface state. Fitting the data at different energies, we can recalculate the LDOS originating from the Dirac band without the contribution of the bulk bands or incoherent tunneling effects. ' article_processing_charge: No article_type: original author: - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: J G full_name: Analytis, J G last_name: Analytis - first_name: J H full_name: Chu, J H last_name: Chu - first_name: I R full_name: Fisher, I R last_name: Fisher - first_name: A full_name: Kapitulnik, A last_name: Kapitulnik citation: ama: Alpichshev Z, Analytis JG, Chu JH, Fisher IR, Kapitulnik A. STM imaging of a bound state along a step on the surface of the topological insulator Bi2Te3. Physical Review B - Condensed Matter and Materials Physics. 2011;84(4). doi:10.1103/PhysRevB.84.041104 apa: Alpichshev, Z., Analytis, J. G., Chu, J. H., Fisher, I. R., & Kapitulnik, A. (2011). STM imaging of a bound state along a step on the surface of the topological insulator Bi2Te3. Physical Review B - Condensed Matter and Materials Physics. American Physical Society. https://doi.org/10.1103/PhysRevB.84.041104 chicago: Alpichshev, Zhanybek, J G Analytis, J H Chu, I R Fisher, and A Kapitulnik. “STM Imaging of a Bound State along a Step on the Surface of the Topological Insulator Bi2Te3.” Physical Review B - Condensed Matter and Materials Physics. American Physical Society, 2011. https://doi.org/10.1103/PhysRevB.84.041104. ieee: Z. Alpichshev, J. G. Analytis, J. H. Chu, I. R. Fisher, and A. Kapitulnik, “STM imaging of a bound state along a step on the surface of the topological insulator Bi2Te3,” Physical Review B - Condensed Matter and Materials Physics, vol. 84, no. 4. American Physical Society, 2011. ista: Alpichshev Z, Analytis JG, Chu JH, Fisher IR, Kapitulnik A. 2011. STM imaging of a bound state along a step on the surface of the topological insulator Bi2Te3. Physical Review B - Condensed Matter and Materials Physics. 84(4). mla: Alpichshev, Zhanybek, et al. “STM Imaging of a Bound State along a Step on the Surface of the Topological Insulator Bi2Te3.” Physical Review B - Condensed Matter and Materials Physics, vol. 84, no. 4, American Physical Society, 2011, doi:10.1103/PhysRevB.84.041104. short: Z. Alpichshev, J.G. Analytis, J.H. Chu, I.R. Fisher, A. Kapitulnik, Physical Review B - Condensed Matter and Materials Physics 84 (2011). date_created: 2018-12-11T11:46:10Z date_published: 2011-07-21T00:00:00Z date_updated: 2021-01-12T07:52:44Z day: '21' doi: 10.1103/PhysRevB.84.041104 extern: '1' external_id: arxiv: - '1003.2233' intvolume: ' 84' issue: '4' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/1003.2233 month: '07' oa: 1 oa_version: Preprint publication: Physical Review B - Condensed Matter and Materials Physics publication_status: published publisher: American Physical Society publist_id: '7443' quality_controlled: '1' status: public title: STM imaging of a bound state along a step on the surface of the topological insulator Bi2Te3 type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 84 year: '2011' ... --- _id: '385' abstract: - lang: eng text: 'Scanning tunneling spectroscopy studies on high-quality Bi2Te3 crystals exhibit perfect correspondence to angle-resolved photoemission spectroscopy data, hence enabling identification of different regimes measured in the local density of states (LDOS). Oscillations of LDOS near a step are analyzed. Within the main part of the surface band oscillations are strongly damped, supporting the hypothesis of topological protection. At higher energies, as the surface band becomes concave, oscillations appear, dispersing with a wave vector that may result from a hexagonal warping term. ' author: - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: James full_name: Analytis, James last_name: Analytis - first_name: Jiunhaw full_name: Chu, Jiunhaw last_name: Chu - first_name: Ian full_name: Fisher, Ian last_name: Fisher - first_name: Yulin full_name: Chen, Yulin last_name: Chen - first_name: Zhixun full_name: Shen, Zhixun last_name: Shen - first_name: Aiping full_name: Fang, Aiping last_name: Fang - first_name: Aharon full_name: Kapitulnik, Aharon last_name: Kapitulnik citation: ama: Alpichshev Z, Analytis J, Chu J, et al. STM imaging of electronic waves on the surface of Bi2Te3 Topologically protected surface states and hexagonal warping effects. Physical Review Letters. 2010;104(1). doi:10.1103/PhysRevLett.104.016401 apa: Alpichshev, Z., Analytis, J., Chu, J., Fisher, I., Chen, Y., Shen, Z., … Kapitulnik, A. (2010). STM imaging of electronic waves on the surface of Bi2Te3 Topologically protected surface states and hexagonal warping effects. Physical Review Letters. American Physical Society. https://doi.org/10.1103/PhysRevLett.104.016401 chicago: Alpichshev, Zhanybek, James Analytis, Jiunhaw Chu, Ian Fisher, Yulin Chen, Zhixun Shen, Aiping Fang, and Aharon Kapitulnik. “STM Imaging of Electronic Waves on the Surface of Bi2Te3 Topologically Protected Surface States and Hexagonal Warping Effects.” Physical Review Letters. American Physical Society, 2010. https://doi.org/10.1103/PhysRevLett.104.016401. ieee: Z. Alpichshev et al., “STM imaging of electronic waves on the surface of Bi2Te3 Topologically protected surface states and hexagonal warping effects,” Physical Review Letters, vol. 104, no. 1. American Physical Society, 2010. ista: Alpichshev Z, Analytis J, Chu J, Fisher I, Chen Y, Shen Z, Fang A, Kapitulnik A. 2010. STM imaging of electronic waves on the surface of Bi2Te3 Topologically protected surface states and hexagonal warping effects. Physical Review Letters. 104(1). mla: Alpichshev, Zhanybek, et al. “STM Imaging of Electronic Waves on the Surface of Bi2Te3 Topologically Protected Surface States and Hexagonal Warping Effects.” Physical Review Letters, vol. 104, no. 1, American Physical Society, 2010, doi:10.1103/PhysRevLett.104.016401. short: Z. Alpichshev, J. Analytis, J. Chu, I. Fisher, Y. Chen, Z. Shen, A. Fang, A. Kapitulnik, Physical Review Letters 104 (2010). date_created: 2018-12-11T11:46:10Z date_published: 2010-01-04T00:00:00Z date_updated: 2021-01-12T07:52:39Z day: '04' doi: 10.1103/PhysRevLett.104.016401 extern: '1' intvolume: ' 104' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/pdf/0908.0371.pdf month: '01' oa: 1 oa_version: None publication: Physical Review Letters publication_status: published publisher: American Physical Society publist_id: '7444' status: public title: STM imaging of electronic waves on the surface of Bi2Te3 Topologically protected surface states and hexagonal warping effects type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 104 year: '2010' ...