Non-linear current and dynamical quantum phase transitions in the flux-quenched Su-Schrieffer-Heeger model

TL;DR

This paper studies how a magnetic flux quench in the 1D Su-Schrieffer-Heeger model induces persistent currents and dynamical quantum phase transitions, revealing nonlinear effects beyond linear response theory.

Contribution

It demonstrates the emergence of persistent currents and dynamical quantum phase transitions in the flux-quenched SSH model, highlighting nonlinear dynamical phenomena in topological systems.

Findings

Flux quench induces finite stationary current in the model.

Persistent current exists in the thermodynamic limit.

Dynamical quantum phase transitions occur within the same topological class.

Abstract

We investigate the dynamical effects of a magnetic flux quench in the Su-Schrieffer-Heeger model in a one-dimensional ring geometry. We show that, even when the system is initially in the half-filled insulating state, the flux quench induces a time-dependent current that eventually reaches a finite stationary value. Such persistent current, which exists also in the thermodynamic limit, cannot be captured by the linear response theory and is the hallmark of nonlinear dynamical effects occurring in the presence of dimerization. Moreover, we show that, for a range of values of dimerization strength and initial flux, the system exhibits dynamical quantum phase transitions, despite the quench is performed within the same topological class of the model.