Decay of Polarons and Molecules in a Strongly Polarized Fermi Gas

TitleDecay of Polarons and Molecules in a Strongly Polarized Fermi Gas
Publication TypeJournal Article
Year of Publication2010
AuthorsBruun, GM, Massignan, P
Refereed DesignationRefereed
JournalPhys. Rev. Lett.
Volume105
Issue2
Pagination020403
Date PublishedJul
Abstract

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.

URLhttp://link.aps.org/doi/10.1103/PhysRevLett.105.020403
DOI10.1103/PhysRevLett.105.020403
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