报告人：Prof. Wensheng (Vincent) Liu，University of Pittsburgh

报告时间：6月28日（周一）上午10:30

报告地点：引力实验中心三楼会议室

摘要：

A number of condensed matter concepts and models have been explored in cold atomic systems, which provide a highly controllable environment. One such system is spin-imbalanced fermions.  In this talk, I will report some of its intriguing properties.  In 3D, the combined effect of Fermi surface mismatch and mass imbalance creates the possibility of discovering a new kind of pairing state---breached pair superfluidity (BP), conceptually different than the well-known BCS and Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)  hases. Novel unique features as well as some numerical evidences of the state will be discussed. In 1D, the effect of spin imbalance is also remarkable. Spin-charge separation previously known as the characteristic of electrons in one-dimensional solids does not occur. A first correct effective model of the Tomonaga-Luttinger liquid type is constructed for arbitrary spin polarization from Bethe ansatz and conformal field theory. Dimensional crossover is then analyzed by renormalization group.  Towards exact solutions, I will report a breakthrough in simplifying coupled thermodynamic Bethe ansatz (TBA) integral equations, whose physics is exact but notoriously difficult to understand.  The simplified TBA equations provide a precise understanding of the 1D system at strong attractive interaction and relatively low temperature and yet are simple enough to be mastered by non-experts comparing with experiments.