From periodically driven double wells to volcano potentials: Quantum dynamics

TL;DR

This paper explores how periodic driving of a double well potential can create a volcano potential, and studies the resulting quantum dynamics, revealing particle escape due to resonance states.

Contribution

It demonstrates how to generate a volcano potential from a double well through periodic driving and analyzes the quantum dynamics using a generalized Ehrenfest's theorem.

Findings

Particle escapes from the central well in the volcano potential.

Coupling of mean position and wave packet width influences escape dynamics.

Resonance states support particle escape in the volcano potential.

Abstract

We consider the dynamics of a particle confined in a double well potential which is subjected to a periodic drive. In the case of deep and well separated wells, we find that by adjusting the parameters of the drive we can generate, to a very good approximation, a volcano potential. The quantum dynamics in this volcano potential is studied by a variation of what can be called a generalized Ehrenfest's theorem. We find that the coupling of the mean position and the width of the wave packet in this dynamics causes the particle to escape from the central well in accordance with the fact that the volcano potential only supports resonance states.