2016/04/30 by Zhoushen Huang, Alexander V. Balatsky · 1 citation
Physics and Astronomy · #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.117.086802
published as Phys. Rev. Lett. 117, 086802 (2016) · 5 pages, 2 figures, plus supplementary. v2: fixed typos, updated references, added a new appendix on a 1D 3-band model exhibiting symmetry-protected DQPT. To appear in Phys. Rev. Lett
arxiv created 2016/08/02 · arxiv updated 2016/08/17
A sudden quantum quench of a Bloch band from one topological phase toward another has been shown to exhibit an intimate connection with the notion of a dynamical quantum phase transition (DQPT), where the returning probability of the quenched state to the initial state---i.e. the Loschmidt echo---vanishes at critical times \t*\. Analytical results so far are limited to two-band models, leaving the exact relation between topology and DQPT unclear. In this work, we show that for a general multi-band system, a robust DQPT relies on the existence of nodes (i.e. zeros) in the wavefunction overlap between the initial band and the post-quench energy eigenstates. These nodes are topologically protected if the two participating wavefunctions have distinctive topological indices. We demonstrate these ideas in detail for both one and two spatial dimensions using a three-band generalized Hofstadter model. We also discuss possible experimental observations.