Experimental Observation of Berry's Phase of the Lorentz Group
Henrik Svensmark, P. Dimon
Berry's phase of the Lorentz group has been measured in a system of connected nonlinear electronic oscillators. Each oscillator was driven so that it was in the vicinity of a period-doubling bifurcation where the response to a small perturbation transforms similarly to a Lorentz boost of a spinor. By connecting the output of one oscillator to the input of the next, it was possible to make a closed loop on a hyperboloid (the invariant surface of the Lorentz group), the enclosed area of which is Berry's phase. Good agreement between theory and experiment is found.
Physical Review Letters•Dec 19, 1994•19 citations