Breakdown of integrability in a quasi-1D ultracold bosonic gas
In a quasi 1D atomic Bose gas virtual excitations of higher radial modes in effective three-body collisions violate integrability and give rise to thermalization.
The estimated thermalization rates are consistent with recent experimental results in quasi-1D dynamics of ultracold atoms.
For two isolated 1d Bose gases the coherence factor exhibit a universal sub-exponential coherence decay in perfect agreement with Luttinger Liquid theory. For coupled 1d Bose gases the coherence factor is observed to approach a non-zero equilibrium value, the matter wave equivalent of phase locking two lasers by injection.
A strictly 1D chain of particles in classical physics is integrable. Previously it was believed that in a quasi-1D atomic Bose gas trapped in a tightly confining waveguide the freeze-out of transversal excitations in two body collisions leads to the demise of thermalization and will eventually make the system integrable. This was not compatible with our recent experiments with very cold quasi 1D BECs having a chemical potential μ < 0.3 hω/2π and a temperature kBT < 0.2 h&omega/2π.
Literature:
I. Mazets, T. Schumm, J. Schmiedmayer
Breakdown of Integrability in a Quasi-1D Ultracold Bosonic Gas
Phys. Rev. Lett. 100, 210403 (2008).
