Cold atoms, the Efimov effect and limit cycles

by Stefan Floerchinger (CERN)

Monday 15 Apr 2013, 14:00 → 15:00 Europe/Zurich

EPFL, Cubotron 727 (EPFL)

I discuss a quantum field theoretic description of strongly interacting cold atoms based on the non-perturbative renormalization group. For identical bosons or fermionic atoms with three components one finds an infinite set of three-body bound states (Efimov effect). It arises from a periodic scale-dependence of the running couplings. I also comment on recent experimental tests using ultracold atoms. Extending the calculation to nonzero density and temperature one finds that a “trion phase” separates a “Color superfluid”-BCS and a -BEC phase with interesting quantum phase transitions for T=0.