Please wait a minute...
Frontiers of Physics

ISSN 2095-0462

ISSN 2095-0470(Online)

CN 11-5994/O4

邮发代号 80-965

2019 Impact Factor: 2.502

Frontiers of Physics  2022, Vol. 17 Issue (3): 33501   https://doi.org/10.1007/s11467-021-1122-5
  本期目录
Complex energy plane and topological invariant in non-Hermitian systems
Annan Fan1, Shi-Dong Liang1,2()
1. School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
2. State Key Laboratory of Optoelectronic Material and Technology, and Guangdong Province Key Laboratory of Display Material and Technology, Sun Yat-Sen University, Guangzhou 510275, China
 全文: PDF(1310 KB)  
Abstract

Non-Hermitian systems as theoretical models of open or dissipative systems exhibit rich novel physical properties and fundamental issues in condensed matter physics. We propose a generalized local–global correspondence between the pseudo-boundary states in the complex energy plane and topological invariants of quantum states. We find that the patterns of the pseudo-boundary states in the complex energy plane mapped to the Brillouin zone are topological invariants against the parameter deformation. We demonstrate this approach by the non-Hermitian Chern insulator model. We give the consistent topological phases obtained from the Chern number and vorticity. We also find some novel topological invariants embedded in the topological phases of the Chern insulator model, which enrich the phase diagram of the non-Hermitian Chern insulators model beyond that predicted by the Chern number and vorticity. We also propose a generalized vorticity and its flipping index to understand physics behind this novel local–global correspondence and discuss the relationships between the local–global correspondence and the Chern number as well as the transformation between the Brillouin zone and the complex energy plane. These novel approaches provide insights to how topological invariants may be obtained from local information as well as the global property of quantum states, which is expected to be applicable in more generic non-Hermitian systems.

Key wordstopological invariant    Chern number    non-Hermitian system
收稿日期: 2021-09-01      出版日期: 2021-11-23
Corresponding Author(s): Shi-Dong Liang   
 引用本文:   
. [J]. Frontiers of Physics, 2022, 17(3): 33501.
Annan Fan, Shi-Dong Liang. Complex energy plane and topological invariant in non-Hermitian systems. Front. Phys. , 2022, 17(3): 33501.
 链接本文:  
https://academic.hep.com.cn/fop/CN/10.1007/s11467-021-1122-5
https://academic.hep.com.cn/fop/CN/Y2022/V17/I3/33501
1 R. El-Ganainy , K. G. Makris , M. Khajavikhan , Z. H. Musslimani , S. Rotter , and D. N. Christodoulides , NonHermitian physics and PT symmetry, Nat. Phys. 14 (1), 11 (2018)
https://doi.org/10.1038/nphys4323
2 Z. Gong , Y. Ashida , K. Kawabata , K. Takasan , S. Higashikawa , and M. Ueda , Topological phases of nonHermitian systems, Phys. Rev. X 8 (3), 031079 (2018)
https://doi.org/10.1103/PhysRevX.8.031079
3 K. Kawabata , K. Shiozaki , M. Ueda , and M. Sato , Symmetry and topology in non-Hermitian physics, Phys. Rev. X 9 (4), 041015 (2019)
https://doi.org/10.1103/PhysRevX.9.041015
4 M. He , H. Sun , and L. H. Qing , Topological insulator: Spintronics and quantum computations, Front. Phys. 14 (4), 43401 (2019)
https://doi.org/10.1007/s11467-019-0893-4
5 V. Y. Chernyak , J. R. Klein , and N. A. Sinitsyn , Quantization and fractional quantization of currents in periodically driven stochastic systems (I): Average currents, J. Chem. Phys. 136 (15), 154107 (2012)
https://doi.org/10.1063/1.3703328
6 J. Qi , H. Liu , H. Jiang , and X. C. Xie , Dephasing effects in topological insulators, Front. Phys. 14 (4), 43403 (2019)
https://doi.org/10.1007/s11467-019-0907-2
7 S. D. Liang and G. Y. Huang , Topological invariance and global Berry phase in non-Hermitian systems, Phys. Rev. A 87 (1), 012118 (2013)
https://doi.org/10.1103/PhysRevA.87.012118
8 A. Mostafazadeh , Pseudo-Hermitian representation of quantum mechanics, Int. J. Geom. Methods Mod. Phys. 07 (07), 1191 (2020)
https://doi.org/10.1142/S0219887810004816
9 A. Mostafazadeh , Energy observable for a quantum system with a dynamical Hilbert space and a global geometric extension of quantum theory, Phys. Rev. D 98 (4), 046022 (2018)
https://doi.org/10.1103/PhysRevD.98.046022
10 Y. Chen and H. Zhai , Hall conductance of a non-Hermitian Chern insulator, Phys. Rev. B 98 (24), 245130 (2018)
https://doi.org/10.1103/PhysRevB.98.245130
11 Y. X. Zhao , Equivariant PT-symmetric real Chern insulators, Front. Phys. 15 (1), 13603 (2020)
https://doi.org/10.1007/s11467-019-0943-y
12 A. Fan , G. Y. Huang , and S. D. Liang , Complex Berry curvature pair and quantum Hall admittance in nonHermitian systems, J. Phys. Commun. 4 (11), 115006 (2020)
https://doi.org/10.1088/2399-6528/abcab6
13 Q. Niu , Advances on topological materials, Front. Phys. 15 (4), 43601 (2020)
https://doi.org/10.1007/s11467-020-0979-z
14 Y. Xu , New physics in old material: Topological and superconducting properties of stanene, Front. Phys. 15 (5), 53202 (2020)
https://doi.org/10.1007/s11467-020-1008-y
15 M. Yang , X. L. Zhang , and W. M. Liu , Tunable topological quantum states in three- and two-dimensional materials, Front. Phys. 10 (2), 161 (2015)
https://doi.org/10.1007/s11467-015-0463-3
16 K. Kawabata , K. Shiozaki , and M. Ueda , Anomalous helical edge states in a non-Hermitian Chern insulator, Phys. Rev. B 98 (16), 165148 (2018)
https://doi.org/10.1103/PhysRevB.98.165148
17 A. Ghatak and T. Das , New topological invariants in nonHermitian systems, J. Phys.: Condens. Matter 31, 263001 (2019)
https://doi.org/10.1088/1361-648X/ab11b3
18 H. Shen , B. Zhen , and L. Fu , Topological band theory for non-Hermitian Hamiltonians, Phys. Rev. Lett. 120 (14), 146402 (2018)
https://doi.org/10.1103/PhysRevLett.120.146402
19 T. E. Lee , Anomalous edge state in a non-Hermitian lattice, Phys. Rev. Lett. 116 (13), 133903 (2016)
https://doi.org/10.1103/PhysRevLett.116.133903
20 V. M. M. Alvarez , J. E. B. Vargas , and L. E. F. F. Torres , Torres, Non-Hermitian robust edge states in one dimension: Anomalous localization and eigenspace condensation at exceptional points, Phys. Rev. B 97, 121401(R) (2018)
https://doi.org/10.1103/PhysRevB.97.121401
21 V. M. M. Alvarez , J. E. B. Vargas , M. Berdakin , and L. E. F. F. Torres , Topological states of non-Hermitian systems, Eur. Phys. J. Spec. Top. 227 (12), 1295 (2018)
https://doi.org/10.1140/epjst/e2018-800091-5
22 K. Kawabata , K. Shiozaki , and M. Ueda , Anomalous helical edge states in a non-Hermitian Chern insulator, Phys. Rev. B 98 (16), 165148 (2018)
https://doi.org/10.1103/PhysRevB.98.165148
23 T. Liu , Y. R. Zhang , Q. Ai , Z. Gong , K. Kawabata , M. Ueda , and F. Nori , Second-order topological phases in nonHermitian systems, Phys. Rev. Lett. 122 (7), 076801 (2019)
https://doi.org/10.1103/PhysRevLett.122.076801
24 F. K. Kunst , E. Edvardsson , J. C. Budich , and E. J. Bergholtz , Biorthogonal bulk–boundary correspondence in non-Hermitian systems, Phys. Rev. Lett. 121 (2), 026808 (2018)
https://doi.org/10.1103/PhysRevLett.121.026808
25 S. Yao and Z. Wang , Edge states and topological invariants of non-Hermitian systems, Phys. Rev. Lett. 121 (8), 086803 (2018)
https://doi.org/10.1103/PhysRevLett.121.086803
26 S. Yao , F. Song , and Z. Wang , Non-Hermitian Chern bands, Phys. Rev. Lett. 121 (13), 136802 (2018)
https://doi.org/10.1103/PhysRevLett.121.136802
27 K. Esaki , M. Sato , K. Hasebe , and M. Kohmoto , Edge states and topological phases in non-Hermitian systems, Phys. Rev. B 84 (20), 205128 (2011)
https://doi.org/10.1103/PhysRevB.84.205128
28 B. Zhu , R. Lu , and S. Chen, PT symmetry in the non-Hermitian Su–Schrieffer–Heeger model with complex boundary potentials, Phys. Rev. A 89 (6), 062102 (2014)
https://doi.org/10.1103/PhysRevA.89.062102
29 H. Jiang , C. Yang , and S. Chen , Topological invariants and phase diagrams for one-dimensional two-band nonHermitian systems without chiral symmetry, Phys. Rev. A 98 (5), 052116 (2018)
https://doi.org/10.1103/PhysRevA.98.052116
30 C. Yin , H. Jiang , L. Li , R. Lu , and S. Chen , Geometrical meaning of winding number and its characterization of topological phases in one-dimensional chiral nonHermitian systems, Phys. Rev. A 97 (5), 052115 (2018)
https://doi.org/10.1103/PhysRevA.97.052115
31 F. Dangel , M. Wagner , H. Cartarius , J. Main , and G. Wunner , Topological invariants in dissipative extensions of the Su–Schrieffer–Heeger model, Phys. Rev. A 98 (1), 013628 (2018)
https://doi.org/10.1103/PhysRevA.98.013628
32 S. Lieu , Topological phases in the non-Hermitian Su– Schrieffer–Heeger model, Phys. Rev. B 97 (4), 045106 (2018)
https://doi.org/10.1103/PhysRevB.97.045106
33 R. Chen , C. Z. Chen , B. Zhou , and D. H. Xu , Finite-size effects in non-Hermitian topological systems, Phys. Rev. B 99 (15), 155431 (2019)
https://doi.org/10.1103/PhysRevB.99.155431
34 D. Leykam , K. Y. Bliokh , C. Huang , Y. D. Chong , and F. Nori , Edge modes, degeneracies, and topological numbers in non-Hermitian systems, Phys. Rev. Lett. 118 (4), 040401 (2017)
https://doi.org/10.1103/PhysRevLett.118.040401
35 J. Y. Lee , J. Ahn , H. Zhou , and A. Vishwanath , Topological correspondence between Hermitian and non-Hermitian systems: Anomalous dynamics, Phys. Rev. Lett. 123 (20), 206404 (2019)
https://doi.org/10.1103/PhysRevLett.123.206404
36 D. C. Brody , Biorthogonal quantum mechanics, J. Phys. A: Math. Theor. 47, 035305 (2014)
https://doi.org/10.1088/1751-8113/47/3/035305
37 D. C. Brody , Consistency of PT-symmetric quantum mechanics J. Phys. A: Math. Theor. 49, 10LT03 (2016)
https://doi.org/10.1088/1751-8113/49/10/10LT03
38 L. Zhang , L. Zhang , S. Niu , and X. J. Liu , Dynamical classification of topological quantum phases, Sci. Bull. (Beijing) 63 (21), 1385 (2018)
https://doi.org/10.1016/j.scib.2018.09.018
39 E. Zeidler , Quantum Field Theory (I): Basics in Mathematics and Physics, Springer, (2006)
40 A. Bohm , A. Mostafazadeh , H. Koizumi , Q. Niu , and J. Zwanziger , The Geometric Phase in Quantum Systems, Springer, New York, (2003)
41 D. Xiao , M. C. Chang , and Q. Niu , Berry phase effects on electronic properties, Rev. Mod. Phys. 82 (3), 1959 (2010)
https://doi.org/10.1103/RevModPhys.82.1959
42 G. von Gersdorff , S. Panahiyan , and W. Chen , Unification of topological invariants in Dirac models, Phys. Rev. B 103 (24), 245146 (2021)
https://doi.org/10.1103/PhysRevB.103.245146
43 W. Chen , M. Legner , A. Ruegg , and M. Sigrist , Correlation length, universality classes, and scaling laws associated with topological phase transitions, Phys. Rev. B 95 (7), 075116 (2017)
https://doi.org/10.1103/PhysRevB.95.075116
44 F. Bernardini , J. Mittleman , H. Rushmeier , C. Silva , and G. Taubin , The Ball–Pivoting algorithm for surface reconstruction, IEEE Trans. Vis. Comput. Graph. 5 (4), 349 (1999)
https://doi.org/10.1103/PhysRevB.95.075116
45 W. Chen , M. Sigrist , and A. P. Schnyder , Scaling theory of Z2 topological invariants, J. Phys.: Condens. Matter 28 (36), 365501 (2016)
https://doi.org/10.1088/0953-8984/28/36/365501
46 W. Chen and A. P. Schnyder , Universality classes of topological phase transitions with higher-order band crossing, New J. Phys. 21 (7), 073003 (2019)
https://doi.org/10.1088/1367-2630/ab2a2d
47 X. G. Wen , A theory of 2+1D bosonic topological orders, Natl. Sci. Rev. 3 (1), 68 (2016)
https://doi.org/10.1093/nsr/nwv077
48 X. G. Wen , Topological orders in rigid states, Int. J. Mod. Phys. B 04 (02), 239 (1990)
https://doi.org/10.1142/S0217979290000139
49 S. Kou , Z. Weng , and X. Wen , Mutual Chern–Simons theory and its applications in condensed matter physics, Front. Phys. 2 (1), 31 (2007)
https://doi.org/10.1007/s11467-007-0004-9
50 A. Fan , S. D. Liang , submitted to Annalen der Physik
51 A. Fan , Ph. D. dissertation, Sun Yat-Sen University, Guangzhou, China, 2021
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed