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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  2020, Vol. 15 Issue (1): 13603   https://doi.org/10.1007/s11467-019-0943-y
  本期目录
Equivariant PT-symmetric real Chern insulators
Y. X. Zhao1,2()
1. National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
2. Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
 全文: PDF(737 KB)  
Abstract

It was understood that Chern insulators cannot be realized in the presence of PT symmetry. In this paper, we reveal a new class of PT-symmetric Chern insulators, which has internal degrees of freedom forming real representations of a symmetry group with a complex endomorphism field. As a generalization to the conventional 2n-dimensional Chern insulators with integer n≥1, these PT-symmetric Chern insulators have the n-th complex Chern number as their topological invariant, and have a Zclassification given by the equivariant orthogonal K theory. Thus, in a fairly different sense, there exist ubiquitously Chern insulators with PT symmetry. By generalizing the Thouless charge pump argument, we find that, for a PT-symmetric Chern insulator with Chern number υ, there are equally many υ flavors of coexisting left- and right-handed chiral modes. Chiral modes with opposite chirality are complex conjugates to each other as complex representations of the internal symmetry group, but are not isomorphic. For the physical dimensionality d = 2, the PT-symmetric Chern insulators may be realized in artificial systems including photonic crystals and periodic mechanical systems.

Key wordstopological insulator    Chern insulator
收稿日期: 2019-08-12      出版日期: 2019-12-12
Corresponding Author(s): Y. X. Zhao   
 引用本文:   
. [J]. Frontiers of Physics, 2020, 15(1): 13603.
Y. X. Zhao. Equivariant PT-symmetric real Chern insulators. Front. Phys. , 2020, 15(1): 13603.
 链接本文:  
https://academic.hep.com.cn/fop/CN/10.1007/s11467-019-0943-y
https://academic.hep.com.cn/fop/CN/Y2020/V15/I1/13603
1 K. Klitzing, G. Dorda, and M. Pepper, New method for high-accuracy determination of the fine-structure constant based on quantized Hall resistance, Phys. Rev. Lett. 45(6), 494 (1980)
https://doi.org/10.1103/PhysRevLett.45.494
2 R. B. Laughlin, Quantized Hall conductivity in two dimensions, Phys. Rev. B 23(10), 5632 (1981)
https://doi.org/10.1103/PhysRevB.23.5632
3 D. J. Thouless, M. Kohmoto, M. P. Nightingale, and M. den Nijs, Quantized Hall conductance in a twodimensional periodic potential, Phys. Rev. Lett. 49(6), 405 (1982)
https://doi.org/10.1103/PhysRevLett.49.405
4 F. D. M. Haldane, Model for a quantum Hall effect without Landau levels: Condensed-matter realization of the “parity anomaly”, Phys. Rev. Lett. 61(18), 2015 (1988)
https://doi.org/10.1103/PhysRevLett.61.2015
5 G. E. Volovik, Universe in a Helium Droplet, Oxford University Press, Oxford UK, 2003
6 R. Yu, W. Zhang, H. J. Zhang, S. C. Zhang, X. Dai, and Z. Fang, Quantized anomalous Hall effect in magnetic topological insulators, Science 329(5987), 61 (2010)
https://doi.org/10.1126/science.1187485
7 C. Z. Chang, J. Zhang, X. Feng, J. Shen, Z. Zhang, M. Guo, K. Li, Y. Ou, P. Wei, L. L. Wang, Z. Q. Ji, Y. Feng, S. Ji, X. Chen, J. Jia, X. Dai, Z. Fang, S. C. Zhang, K. He, Y. Wang, L. Lu, X. C. Ma, and Q. K. Xue, Experimental observation of the quantum anomalous Hall effect in a magnetic topological insulator, Science 340(6129), 167 (2013)
https://doi.org/10.1126/science.1234414
8 M. Z. Hasan and C. L. Kane, Topological insulators, Rev. Mod. Phys. 82(4), 3045 (2010)
https://doi.org/10.1103/RevModPhys.82.3045
9 X. L. Qi and S. C. Zhang, Topological insulators and superconductors, Rev. Mod. Phys. 83(4), 1057 (2011)
https://doi.org/10.1103/RevModPhys.83.1057
10 Y. X. Zhao, A. P. Schnyder, and Z. D. Wang, Unified theory of PTand CPinvariant topological metals and nodal superconductors, Phys. Rev. Lett. 116(15), 156402 (2016)
https://doi.org/10.1103/PhysRevLett.116.156402
11 Y. X. Zhao and Y. Lu, PT-symmetric real Dirac fermions and semimetals, Phys. Rev. Lett. 118(5), 056401 (2017)
https://doi.org/10.1103/PhysRevLett.118.056401
12 C. Fang, Y. Chen, H. Y. Kee, and L. Fu, Topological nodal line semimetals with and without spin–orbital coupling, Phys. Rev. B. 92(8), 081201 (2015)
https://doi.org/10.1103/PhysRevB.92.081201
13 R. Yu, H. Weng, Z. Fang, X. Dai, and X. Hu, Topological node-line semimetal and Dirac semimetal state in antiperovskite Cu3PdN, Phys. Rev. Lett. 115(3), 036807 (2015)
https://doi.org/10.1103/PhysRevLett.115.036807
14 Y. Kim, B. J. Wieder, C. L. Kane, and A. M. Rappe, Dirac line nodes in inversion-symmetric crystals, Phys. Rev. Lett. 115(3), 036806 (2015)
https://doi.org/10.1103/PhysRevLett.115.036806
15 D. W. Zhang, Y. X. Zhao, R. B. Liu, Z. Y. Xue, S. L. Zhu, and Z. D. Wang, Quantum simulation of exotic PT-invariant topological nodal loop bands with ultracold atoms in an optical lattice, Phys. Rev. A 93(4), 043617 (2016)
https://doi.org/10.1103/PhysRevA.93.043617
16 W. B. Rui, Y. X. Zhao, and A. P. Schnyder, Topological transport in Dirac nodal-line semimetals, Phys. Rev. B 97, 161113 (2018)
https://doi.org/10.1103/PhysRevB.97.161113
17 L. Lu, J. D. Joannopoulos, and M. Soljačići, Topological photonics, Nat. Photon. 8, 821 (2014)
https://doi.org/10.1038/nphoton.2014.248
18 J. Joannopoulos, R. Meade, and J. Winn, Photonic Crystals: Molding the Flow of Light, Princeton University Press, 1995
19 E. Prodan and C. Prodan, Topological phonon modes and their role in dynamic instability of microtubules, Phys. Rev. Lett. 103(24), 248101 (2009)
https://doi.org/10.1103/PhysRevLett.103.248101
20 C. L. Kane and T. C. Lubensky, Topological boundary modes in isostatic lattices, Nat. Phys. 10, 39 (2014)
https://doi.org/10.1038/nphys2835
21 P. Wang, L. Lu, and K. Bertoldi, Topological phononic crystals with one-way elastic edge waves, Phys. Rev. Lett. 115(10), 104302 (2015)
https://doi.org/10.1103/PhysRevLett.115.104302
22 M. F. Atiyah and D. W. Anderson, K-Theory, WA Benjamin New York, 1967
23 M. F. Atiyah, K-theory and reality, Q. J. Math. 17(1), 367 (1966)
https://doi.org/10.1093/qmath/17.1.367
24 G. Segal, Equivariant K-theory, Publications mathématiques de l’IHÉS 34(1), 129 (1968)
https://doi.org/10.1007/BF02684593
25 D. J. Thouless, Quantization of particle transport, Phys. Rev. B 27(10), 6083 (1983)
https://doi.org/10.1103/PhysRevB.27.6083
26 Q. Niu and D. J. Thouless, Quantised adiabatic charge transport in the presence of substrate disorder and manybody interaction,J. Phys. Math. Gen. 17(12), 2453 (1984)
https://doi.org/10.1088/0305-4470/17/12/016
27 L. Fu and C. L. Kane, Time reversal polarization and a Z2 adiabatic spin pump, Phys. Rev. B 74(19), 195312 (2006)
https://doi.org/10.1103/PhysRevB.74.195312
28 Y. Yu, Y. S. Wu, and X. Xie, Bulk-edge correspondence, spectral flow and Atiyah–Patodi–Singer theorem for the invariant in topological insulators, Nucl. Phys. B 916, 550 (2017)
29 T. Bröcker and T. tom Dieck, Representations of Compact Lie Groups, Springer Science & Business Media, 2013
30 F. J. Dyson, The threefold way, J. Math. Phys. 3(6), 1199 (1962)
https://doi.org/10.1063/1.1703863
31 Here we consider the case of strong topological insulators, which means the BZ torus is treated as a sphere.
32 A. Kitaev, V. Lebedev, and M. Feigel’man, Periodic table for topological insulators and superconductors, AIP Conf. Proc. 1134, 22 (2009)
https://doi.org/10.1063/1.3149495
33 J. Zak, Berry’s phase for energy bands in solids, Phys. Rev. Lett. 62(23), 2747 (1989)
https://doi.org/10.1103/PhysRevLett.62.2747
34 B. A. Bernevig, T. L. Hughes, and S. C. Zhang, Quantum spin Hall effect and topological phase transition in HgTe quantum wells, Science 314(5806), 1757 (2006)
https://doi.org/10.1126/science.1133734
35 C. L. Kane and E. J. Mele, Z2 topological order and the quantum spin Hall effect, Phys. Rev. Lett. 95(14), 146802 (2005)
https://doi.org/10.1103/PhysRevLett.95.146802
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