### Description

In this talk, I will consider an atomic Fermi gas in the
limit of extreme spin imbalance, where one has a single
spin-down impurity atom interacting attractively with a
spin-up atomic Fermi gas. By constructing variational wave
functions for polarons, molecules and trimers, I will
explore the quantum phase transitions between each of these
bound states as a function of mass ratio and interaction
strength. I will show that Fulde-Ferrell-Larkin-Ovchinnikov
(FFLO) pairing is mostly superceded by the formation of a
p-wave trimer, which can be viewed as a FFLO molecule that
has bound an additional majority atom. When the mass of
impurity atom is sufficiently light, I find that these
transitions lie outside the region of superfluid-normal
phase separation in spin-imbalanced Fermi gases and should
thus be observable in experiment, unlike the well-studied
equal-mass case.

### Primary author

Dr
Meera Parish
(University of Cambridge)