Subject：Fermi gases close to a p-wave interaction resonance

Speaker：Dr.Zhenhua Yu(Sun Yat-Sen University)

Time：3:00pm,22th July,2016

Place:lecture hall,4F, Pinbiao Building of Institute，WIPM

Abstract：

The successful application of s-wave “contact” to unitary Fermi gases exemplifies the importance of few-body correlations in understanding strongly interacting many-body systems. Recent experimentally measured radio-frequency spectrum and momentum distribution of three-dimensional Fermi gases close to a p-wave Feshbach Resonance show universal tails different from the s-wave case. We emphasise that the difference is due to the necessity of using both the scattering volume v and the effective range R to parameterise the two-body p-wave interatomic interaction, and show that by including two-body correlations at short range, the interaction effects of the system are captured by two contacts, C_v and C_R, which are related to the variation of energy with v and R in two adiabatic theorems . Based on the two contacts, we derive the universal properties of the system regarding momentum distribution, radio-frequency and photo-association spectroscopies, and pressure and virial relations. We also establish coupled rate equations to explain the time evolution of the p-wave contacts observed in the quench experiment.

Beyond two-body correlations at short range, p-wave resonances are predicted to give rise to universal super Efimov three-body bound states in two-dimensions. We use the hyper-spherical formalism and show that these new universal states originate from an emergent effective potential, which is different from the one responsible for the familiar Efimov states. The three-body correlation due to the super Efimov physics is expected to give rise to three-body contact structures in observables.