Transport discovery of emerging robust helical surface States in Z2 = 0 systems.
We study the possibility of realizing robust helical surface states in Z(2) = 0 systems. We find that the combination of anisotropy and finite-size confinement leads to the emergence of robust helical edge states in both two-dimensional and three-dimensional Z(2) = 0 systems. By investigating an anisotropic Bernevig-Hughes-Zhang model in a finite sample, we demonstrate that the transport manifestation of the surface states is robust against nonmagnetic disorder, resembling that of a Z(2) = 1 phase. Notably, the effective energy gap of the robust helical states can be efficiently engineered, allowing for potential applications as valley filters and valley valves. The realization of emerging robust helical surface states in realistic materials is also discussed.
Department of Physics and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou 215006, China.
Hua
H
Jiang
International Center for Quantum Materials, Peking University, Beijing 100871, China and Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
Haiwen
H
Liu
International Center for Quantum Materials, Peking University, Beijing 100871, China and Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
Ji
J
Feng
International Center for Quantum Materials, Peking University, Beijing 100871, China and Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
Qingfeng
Q
Sun
International Center for Quantum Materials, Peking University, Beijing 100871, China and Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
X C
XC
Xie