Induced Violation of Time-Reversal Invariance in the Regime of Weakly Overlapping Resonances

TL;DR

This paper investigates how time-reversal invariance can be partially broken in a chaotic microwave cavity, using random-matrix theory to analyze scattering amplitudes and test T-violation predictions.

Contribution

It extends the random-matrix approach to T-violation in scattering and provides the most precise experimental validation within this framework to date.

Findings

Partial T-invariance breaking observed with a magnetized ferrite

Theoretical predictions successfully match several properties of scattering amplitudes

Extended random-matrix model accurately describes T-violation effects

Abstract

We measure the complex scattering amplitudes of a flat microwave cavity (a "chaotic billiard"). Time-reversal T-invariance is partially broken by a magnetized ferrite placed within the cavity. We extend the random-matrix approach to T-violation in scattering, fit some of the properties of the scattering amplitudes, and then successfully predict others. Our work constitutes the most precise test of the theoretical approach to T-violation within the framework of random-matrix theory so far available.