Forbidden activation levels in a non-stationary tunneling process

TL;DR

This paper investigates how time-varying barriers affect quantum tunneling, revealing that strong perturbations can prevent activation at certain energies if they decay faster than 1/t^2.

Contribution

It introduces a detailed analysis of forbidden activation levels in non-stationary tunneling, combining numerical and analytical methods to identify decay conditions.

Findings

Spectral widening occurs due to barrier variation.

Strong perturbations can prevent activation at specific energies.

Forbidden activation levels occur when perturbations decay faster than 1/t^2.

Abstract

Tunneling in the presence of an opaque barrier, part of which varies in time, is investigated numerically and analytically in one dimension. Clearly, due to the varying barrier a tunneling particle experiences spectral widening. However, in the case of strong perturbations, the particles' activation to certain energies is avoided. We show that this effect occurs only when the perturbation decays faster than 1/t^2.