Dynamical thermalization of Bose-Einstein condensate in Bunimovich stadium

LEONARDO ERMANN; EDUARDO VERGINI; DIMA L. SHEPELYANSKY

EUROPHYSICS LETTERS

EPL ASSOCIATION

Lugar: Bologna; Año: 2015 vol. 111 p. 50009 - 50016

0295-5075

We study numerically the wave function evolution of a Bose-Einstein condensate in aBunimovich stadium billiard being governed by the Gross-Pitaevskii equation. We show that for a moderate nonlinearity, above a certain threshold, there is emergence of dynamical thermalization which leads to the Bose-Einstein probability distribution over the linear eigenmodes of the stadium. This distribution is drastically different from the energy equipartition over oscillator degrees of freedom which would lead to the ultra-violet catastrophe. We argue that this interesting phenomenon can be studied in cold-atom experiments.