Scattering of accelerated wave packets

TL;DR

This paper investigates how external time-dependent forces affect wave-packet scattering from reflectionless potentials, revealing conditions under which scattering is suppressed or occurs, especially in complex Kramers-Kronig potentials.

Contribution

It demonstrates that certain time-dependent forces do not induce scattering in complex Kramers-Kronig potentials, extending understanding of wave-packet dynamics under external influences.

Findings

Broad class of forces do not induce scattering in Kramers-Kronig potentials.

Reflectionless property breaks down with broadband initial momentum distribution.

External forces can make potential barriers transparent under specific conditions.

Abstract

Wave-packet scattering from a stationary potential is significantly modified when the wave-packet is subject to an external time-dependent force during the interaction. In the semiclassical limit, wave--packet motion is simply described by Newtonian equations and the external force can, for example, cancel the potential force making a potential barrier transparent. Here we consider wave-packet scattering from reflectionless potentials, where in general the potential becomes reflective when probed by an accelerated wave-packet. In the particular case of the recently-introduced class of complex Kramers-Kronig potentials we show that a broad class of time dependent forces can be applied without inducing any scattering, while there is a breakdown of the reflectionless property when there is a broadband distribution of initial particle momentum, involving both positive and negative components.