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Lujan D, Choe J, Chaudhary S, Ye G, Nnokwe C, Rodriguez-Vega M, He J, Gao FY, Nunley TN, Baldini E, Zhou J, Fiete GA, He R, Li X. Spin-orbit exciton-induced phonon chirality in a quantum magnet. Proc Natl Acad Sci U S A 2024; 121:e2304360121. [PMID: 38457517 PMCID: PMC10945760 DOI: 10.1073/pnas.2304360121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 11/17/2023] [Indexed: 03/10/2024] Open
Abstract
The interplay of charge, spin, lattice, and orbital degrees of freedom in correlated materials often leads to rich and exotic properties. Recent studies have brought new perspectives to bosonic collective excitations in correlated materials. For example, inelastic neutron scattering experiments revealed non-trivial band topology for magnons and spin-orbit excitons (SOEs) in a quantum magnet CoTiO3 (CTO). Here, we report phonon properties resulting from a combination of strong spin-orbit coupling, large crystal field splitting, and trigonal distortion in CTO. Specifically, the interaction between SOEs and phonons endows chirality to two [Formula: see text] phonon modes and leads to large phonon magnetic moments observed in magneto-Raman spectra. The remarkably strong magneto-phononic effect originates from the hybridization of SOEs and phonons due to their close energy proximity. While chiral phonons have been associated with electronic topology in some materials, our work suggests opportunities may arise by exploring chiral phonons coupled to topological bosons.
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Affiliation(s)
- David Lujan
- Department of Physics, Center of Complex Quantum Systems, The University of Texas at Austin, Austin, TX78712
- Center for Dynamics and Control of Materials, The University of Texas at Austin, Austin, TX78712
| | - Jeongheon Choe
- Department of Physics, Center of Complex Quantum Systems, The University of Texas at Austin, Austin, TX78712
- Center for Dynamics and Control of Materials, The University of Texas at Austin, Austin, TX78712
| | - Swati Chaudhary
- Department of Physics, Center of Complex Quantum Systems, The University of Texas at Austin, Austin, TX78712
- Department of Physics, Northeastern University, Boston, MA02115
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Gaihua Ye
- Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX79409
| | - Cynthia Nnokwe
- Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX79409
| | - Martin Rodriguez-Vega
- Department of Physics, Center of Complex Quantum Systems, The University of Texas at Austin, Austin, TX78712
- Department of Physics, Northeastern University, Boston, MA02115
| | - Jiaming He
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX78712
| | - Frank Y. Gao
- Department of Physics, Center of Complex Quantum Systems, The University of Texas at Austin, Austin, TX78712
- Center for Dynamics and Control of Materials, The University of Texas at Austin, Austin, TX78712
| | - T. Nathan Nunley
- Department of Physics, Center of Complex Quantum Systems, The University of Texas at Austin, Austin, TX78712
- Center for Dynamics and Control of Materials, The University of Texas at Austin, Austin, TX78712
| | - Edoardo Baldini
- Department of Physics, Center of Complex Quantum Systems, The University of Texas at Austin, Austin, TX78712
- Center for Dynamics and Control of Materials, The University of Texas at Austin, Austin, TX78712
| | - Jianshi Zhou
- Center for Dynamics and Control of Materials, The University of Texas at Austin, Austin, TX78712
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX78712
| | - Gregory A. Fiete
- Department of Physics, Northeastern University, Boston, MA02115
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA02139
| | - Rui He
- Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX79409
| | - Xiaoqin Li
- Department of Physics, Center of Complex Quantum Systems, The University of Texas at Austin, Austin, TX78712
- Center for Dynamics and Control of Materials, The University of Texas at Austin, Austin, TX78712
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Zhai G, Zhu Y, Jiang F, Yan Y, Wang S. Spin-selective thermoelectric transport along a vibrating α-helical protein molecule. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:475301. [PMID: 36103873 DOI: 10.1088/1361-648x/ac920c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/14/2022] [Indexed: 06/15/2023]
Abstract
Motivated by the development of bio-thermoelectricity and spin caloritronics, we studied the nonlinear spin-selective transport along a vibratingα-helical protein molecule in the presence of thermal bias by using the standard nonequilibrium Green's function formalism. Our results demonstrate that the thermal bias induces the oscillation of spin-polarization between positive and negative values accompanied by spin current with increasing the chain length. Moreover, even for the very short preparable peptide chains, external electron-phonon interaction can give rise to the spin-selectivity, whereas characteristic electron-phonon interaction can not, but in conjunction with thermal bias, it has an important impact on the total current's direction and the spin-polarized current intensity. Finally, the spin-polarization induced by thermal bias can be modulated by gate-bias much more easily as compared to that induced by electric bias. We conclude that by applying thermal bias and gate-bias,α-helical protein molecules are conducive to the storage of binary digits.
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Affiliation(s)
- Guangwei Zhai
- College of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 200090, People's Republic of China
| | - Yanyan Zhu
- College of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 200090, People's Republic of China
| | - Feng Jiang
- College of Mathematics and Physics, Shanghai University of Electric Power, Shanghai 200090, People's Republic of China
| | - Yonghong Yan
- Department of Physics, Shaoxing University, Shaoxing 312000, People's Republic of China
| | - Shikuan Wang
- Department of Physics, Hangzhou Dianzi University, Hangzhou 310018, People's Republic of China
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