Ratchet Effect in the Quantum Kicked Rotor and its Destruction by Dynamical Localization

TL;DR

This paper investigates how quantum effects suppress the classical ratchet behavior in a quantum kicked rotor, demonstrating the transition from directed motion to dynamical localization.

Contribution

It experimentally demonstrates the destruction of the quantum ratchet effect by dynamical localization in a parity-broken quantum kicked rotor.

Findings

Classical dynamics shows asymmetric momentum distribution with directed motion.

Quantum effects induce dynamical localization, restoring symmetry.

Short-time classical behavior transitions to quantum localization at longer times.

Abstract

We study experimentally a quantum kicked rotor with broken parity symmetry, supporting a ratchet effect due to the presence of a classical accelerator mode. We show that the short-time dynamics is very well described by the classical dynamics, characterized by a strongly asymmetric momentum distribution with directed motion on one side, and an anomalous diffusion on the other. At longer times, quantum effects lead to dynamical localization, causing an asymptotic resymmetrization of the wave function.