Dynamic skin effects in non-Hermitian systems

TL;DR

This paper analytically confirms the dynamical skin effect in non-Hermitian systems, revealing its mechanism involving wave packet spreading and showing that Gaussian wave packets can accelerate and amplify, leading to unique dynamical behaviors.

Contribution

It provides an analytical understanding of the dynamical skin effect in non-Hermitian systems and uncovers the role of wave packet dynamics in this phenomenon.

Findings

Dynamical skin effect exists in non-Hermitian systems under open boundary conditions.

Gaussian wave packets can accelerate and amplify during evolution in non-Hermitian systems.

The dynamic skin effect is caused by both non-Hermitian skin effect and wave packet spreading.

Abstract

We study the time evolution processes of non-Hermitian systems under the open boundary condition and confirm that the dynamical skin effect exists in non-Hermitian systems analytically, and unveil the mechanism of its formation, which is caused by both the non-Hermitian skin effect and the Hermitian wave packet spreading. Furthermore, we find that in contrast to the uniform speed motion in Hermitian situations, the Gaussian wave packet can be accelerated and amplified during its time evolution in non-Hermitian systems. This additional motion is found to be responsible for the dynamic skin effect.