Experimental Observation of Resonance-Assisted Tunneling

TL;DR

This paper reports the first experimental evidence of resonance-assisted tunneling, demonstrating how classical nonlinear resonances can significantly enhance wave tunneling between regular and chaotic regions in a microwave cavity.

Contribution

It provides the first experimental observation of resonance-assisted tunneling using a specially designed microwave cavity with a nonlinear resonance chain.

Findings

Resonance-assisted tunneling increases the tunneling rate and mode line width.

Characteristic plateau and peak structures are observed in the semiclassical limit.

Experimental evidence supports theoretical predictions of resonance effects on tunneling.

Abstract

We present the first experimental observation of resonance-assisted tunneling, a wave phenomenon, where regular-to-chaotic tunneling is strongly enhanced by the presence of a classical nonlinear resonance chain. For this we use a microwave cavity made of oxygen free copper with the shape of a desymmetrized cosine billiard designed with a large nonlinear resonance chain in the regular region. It is opened in a region, where only chaotic dynamics takes place, such that the tunneling rate of a regular mode to the chaotic region increases the line width of the mode. Resonance-assisted tunneling is demonstrated by (i) a parametric variation and (ii) the characteristic plateau and peak structure towards the semiclassical limit.