Open AccessZero-energy corner states protected by generalized chiral symmetry in C 4 symmetric crystals
Author(s) -
Yuzeng Li,
Zhengfang Liu,
Xun-Wei Xu,
QingPing Wu,
Xunwen Xiao,
Meirong Liu,
Lulu Chang,
Ruo-Long Zhang
Publication year - 2021
Publication title -
new journal of physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.584
H-Index - 190
ISSN - 1367-2630
DOI - 10.1088/1367-2630/abf035
Subject(s) - physics , chiral symmetry , lattice (music) , amplitude , polarization (electrochemistry) , condensed matter physics , charge (physics) , topology (electrical circuits) , quantum mechanics , symmetry (geometry) , geometry , combinatorics , chemistry , mathematics , acoustics , quark
We investigated the corner-states characteristics of C 4 -symmetric higher-order topological crystalline insulators. By evaluating the charge polarization and fractional corner charge, we obtained the abundant topological properties for different intercell hoppings amplitudes and identified that the non-trivial fractional corner charges are accompanied by second-order topological corner states. Interestingly, there are two different types of corner states topologically protected by generalized chiral symmetry, which guarantees that both corner states are pinned to zero energy. One of the corner states is localized at the corners like the one protected by generalized chiral symmetry of three-atom sublattice. However, the other corner states are localized at the two sublattices nearest to the corners, which has no counterpart in a lattice with generalized chiral symmetry. Moreover, both of them have robustness against defects and disorder.