Emergence of a New Superfluid Phase in Quasi-2D ³He

³He is a fermionic superfluid that exhibits exotic properties at ultra-low temperatures due to its unconventional p-wave Cooper pairing. The orbital and spin degrees of freedom of ³He Cooper pairs allows for a rich array of possible superfluid phases, which are determined by geometry as well as the thermodynamic properties of the fluid. Much of the current theoretical and experimental interest in ³He has focused on quasi-2D slabs where new phases are predicted to emerge. Our lab has created nanofluidic mechanical resonators capable of both confining ³He and detecting phase transitions over a wide range of pressures and temperatures. In doing so we have observed a new phase transition which is stabilized by confinement and thought to be due to the breaking of translational symmetry within the superfluid slab.