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

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, determine the parameters from some properties of the scattering amplitudes, and successfully predict others. Our work constitutes the most precise test of the random-matrix theoretical approach to T violation so far available.