Sudden jumps and plateaus in the quench dynamics of a Bloch state

TL;DR

This paper investigates the complex quench dynamics of a particle in a Bloch state on a 1D lattice, revealing indefinite jumps and plateaus in probability density, explained by an exactly solvable nonanalytic model.

Contribution

It introduces a detailed analysis of jump and plateau phenomena in wave function dynamics after a quench, supported by an exactly solvable Luttinger-like model.

Findings

Probability density exhibits indefinite jumps and plateaus after a quench.

The dynamics are governed by an exactly solvable nonanalytic model.

Locations and heights of jumps and plateaus are accurately predicted.

Abstract

We take a one-dimensional tight binding chain with periodic boundary condition and put a particle in an arbitrary Bloch state, then quench it by suddenly changing the potential of an arbitrary site. In the ensuing time evolution, the probability density of the wave function at an arbitrary site \emph{jumps indefinitely between plateaus}. This phenomenon adds to a former one in which the survival probability of the particle in the initial Bloch state shows \emph{cusps} periodically, which was found in the same scenario [Zhang J. M. and Yang H.-T., EPL, \textbf{114} (2016) 60001]. The plateaus support the scattering wave picture of the quench dynamics of the Bloch state. Underlying the cusps and jumps is the exactly solvable, nonanalytic dynamics of a Luttinger-like model, based on which, the locations of the jumps and the heights of the plateaus are accurately predicted.