|Title||Decay of Polarons and Molecules in a Strongly Polarized Fermi Gas|
|Publication Type||Journal Article|
|Year of Publication||2010|
|Authors||Bruun, GM, Massignan, P|
|Journal||Phys. Rev. Lett.|
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.