Quench dynamics in the Aubry-Andr\'e-Harper model with \textit{p}-wave superconductivity

TL;DR

This paper investigates the dynamical behavior of the Aubry-André-Harper model with p-wave superconductivity during a quench, revealing distinct signatures in entanglement entropy, wave packet width, and Loschmidt echo across different phases.

Contribution

It provides a detailed numerical analysis of quench dynamics in the AAH model with p-wave pairing, highlighting phase-dependent signatures in entanglement and Loschmidt echo behaviors.

Findings

Entanglement entropy grows as a power law in extended phase

Loschmidt echo oscillates and remains finite in extended phase

In localized phase, entropy saturates and echo decays to zero

Abstract

The Anderson localization phase transition in the Aubry-Andr\'e-Harper (AAH) model with \textit{p}-wave superconducting (SC) pairing is numerically investigated by suddenly changing the on-site potential from zero to various finite values which fall into the extended, critical and localized phase regimes shown in this model. The time evolutions of entanglement entropy (EE), mean width of wave packets and Loschmidt echo of the system exhibit distinct but consistent dynamical signatures in those three phases. Specifically, the EE grows as a power function of time with the exponent of which varies in the extended phase but keeps almost unchanged in the critical phase for different quench parameters. However, if the system is in the localized phase after a quench, the EE grows much slower and will soon get saturated. The time-dependent width of wave packets in the system shows similar behaviors as the EE. In addition, from the perspective of dynamical phase transition, we find that the Loschmidt echo oscillates and always keeps finite when the system is quenched in the extended phase. In contrast, in the critical or localized phase, the echo will reach to zero at some time intervals or will decay almost to zero after a long-time evolution. The universal features of these quantities in the critical phase of the system with various SC pairing amplitudes are also observed.