Probing unitary Fermi gases locally with Bragg spectroscopy

Gases of lithium atoms are trapped and cooled to 30 billionths of a degree above absolute zero using laser cooling techniques. The nature of the gas is now described by quantum mechanics and highly dependent on the interactions between particles. Of particular interest is the behaviour of the gas when atomic collisions are resonantly enhanced, as this may provide insight into outstanding problems in high-energy, nuclear and condensed matter physics. This research observed the formation of a pair-condensate in a resonantly interacting gas using Bragg spectroscopy and showed that it occurs simultaneously with the phase transition to a superfluid.