Eur. Phys. J. B (2013) 86: 367
https://doi.org/10.1140/epjb/e2013-40657-2

Regular Article

Quench dynamics of edge states in 2-D topological insulator ribbons

Department of Physics, Indian Institute of Technology Kanpur, 208016 Kanpur, India

^a e-mail: teslawolf@gmail.com

Received: 3 May 2013
Received in final form: 9 July 2013
Published online: 2 September 2013

Abstract

We study the dynamics of edge states of the two dimensional BHZ Hamiltonian in a ribbon geometry following a sudden quench to the quantum critical point separating the topological insulator phase from the trivial insulator phase. The effective edge state Hamiltonian is a collection of decoupled qubit-like two-level systems which get coupled to bulk states following the quench. We notice a pronounced collapse and revival of the Lochschmidt echo for low-energy edge states illustrating the oscillation of the state between the two edges. We also observe a similar collapse and revival in the spin Hall current carried by these edge states, leading to a persistence of its time-averaged value.