Condensation dynamics in a quenched unitary Fermi gas.

Non-equilibrium phenomena in many-body quantum systems involves the interplay of correlations and dynamics spanning different spatio-temporal scales. We present an experimental study of these dynamics in a two-component Fermi gas following a quench from weak to strong interactions. Starting with a weakly attractive gas in the normal phase, interactions are ramped to the unitarity limit at a range of rates, which involves crossing the normal to superfluid phase transition. We measure the subsequent dynamics of the pair momentum distribution which reveals the timescales for both the formation and condensation of pairs. Furthermore, we show that the contact parameter responds very rapidly to changes in the interaction strength, demonstrating that short-range correlations, based on the occupation of high-momentum modes, evolve far more rapidly than correlations in low-momentum modes necessary for pair condensation.