Disorder induced topological phases

Hsiu-Chuan Hsu^1*, Tsung-Wei Chen², Pok Man Chiu³, Po-Yao Chang³

¹Graduate Institute of Applied Physics, National Chengchi University, Taipei, Taiwan
²Department of physics, National Sun Yat-sen University, Kaohsiung, Taiwan
³Department of physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Hsiu-Chuan Hsu, email:hchsu888@gmail.com

Disorder induced topological phases are shown to exist in equilibrium systems, as well as in quench dynamics. In this talk, I will present our findings in both regimes for the one-dimensional Su-Schrieffer–Heeger (SSH) model. First, I will show the topological Anderson insulating phase in an equilibrium system. For the long-range SSH model, it is shown that disorder drives topological phase transitions between different topological phases. The phase diagram is identified with the calculation of winding number and localization length. The mechanism is explained by band gap renormalization and Anderson localization. Secondly, I will address the disorder induced topology in quench dynamics. The nontrivial topology is confirmed by entanglement spectrum, Berry phase and the quantization of the dynamical Chern number. The role of disorder in quench dynamics will be discussed.

Keywords: Anderson localization, Topological insulators, Green's function methods