Two superconducting microwave billiards have been electromagnetically coupled in a variable way. The spectrum of the entire system has been measured and the spectral statistics analyzed as a function of the coupling strength. It is shown that the results can be understood in terms of a random matrix model of quantum mechanical symmetry breaking -- as e.g. the violation of parity or isospin in nuclear physics.
@article{arxiv.chao-dyn/9810024,
title = {Coupled Microwave Billiards as a Model for Symmetry Breaking},
author = {H. Alt and C. I. Barbosa and H. -D. Graef and T. Guhr and H. L. Harney and R. Hofferbert and H. Rehfeld and A. Richter},
journal= {arXiv preprint arXiv:chao-dyn/9810024},
year = {2009}
}