Non-Hermitian topological phases and dynamical quantum phase transitions: A generic connection

TL;DR

This paper reveals a fundamental link between topological phases and dynamical quantum phase transitions in non-Hermitian systems, supported by theoretical models and an experimental proposal.

Contribution

It establishes a generic connection between topological invariants and DQPTs in non-Hermitian systems, with validation in three lattice models and an experimental setup.

Findings

Number of critical momenta and times relate to topological invariants.

DQPTs occur after quenches from trivial to topological phases.

Experimental verification is proposed using nitrogen-vacancy centers.

Abstract

The dynamical and topological properties of non-Hermitian systems have attracted great attention in recent years. In this work, we establish an intrinsic connection between two classes of intriguing phenomena -- topological phases and dynamical quantum phase transitions (DQPTs) -- in non-Hermitian systems. Focusing on one-dimensional models with chiral symmetry, we find DQPTs following the quench from a trivial to a non-Hermitian topological phase. Moreover, the number of critical momenta and critical time periods of the DQPTs are found to be directly related to the topological invariants of the non-Hermitian system. We further demonstrate our theory in three prototypical non-Hermitian lattice models, the lossy Kitaev chain (LKC), the LKC with next-nearest-neighbor hoppings, and the nonreciprocal Su-Schrieffer-Heeger model. Finally, we present a proposal to experimentally verify the found connection by a nitrogen-vacancy center in diamond.