Decay of Polarons and Molecules in a Strongly Polarized Fermi Gas

作者:Bruun G M*; Massignan P
来源:Physical Review Letters, 2010, 105(2): 020403.
DOI:10.1103/PhysRevLett.105.020403

摘要

The ground state of an impurity immersed in a Fermi sea changes from a polaron to a molecule as the interaction strength is increased. We show here that the coupling between these two states is strongly suppressed due to a combination of phase-space effects and Fermi statistics, and that it vanishes much faster than the energy difference between the two states, thereby confirming the first order nature of the polaron-molecule transition. In the regime where each state is metastable, we find quasiparticle lifetimes which are much longer than what is expected for a usual Fermi liquid. Our analysis indicates that the decay rates are sufficiently slow to be experimentally observable.

  • 出版日期2010-7-8