题 目: Finite angular momentum superfluidity in atomic quantum matter: from center-of-mass p-wave symmetry to Weyl fermions

报告人：刘博（美国匹兹堡大学物理与天文系博士后）

时 间：3月21日（星期一）上午10:00-11:00

地 点：物理学院新楼5楼多功能厅

摘 要: Since the observation of Bose-Einstein condensation and of superfluidity in atomic gases, ultracold quantum gases have become a very versatile tool to explore new quantum states of matter. Because of the highly controllable and clean environment in atomic systems, it is hoped that they will not only provide a perfect simulator of electronic systems, but also opportunities to create new types of quantum states with no counterpart in solids. In this talk, experimentally feasible routes with cold gases based systems to achieve two kinds of new quantum states of matter (i.e., center-of-mass p-wave superfluidity and Weyl superfluids) are proposed. Firstly, the new concept of center-of-mass p-wave superconducting pairing, which can arise from the interplay between spin imbalance and orbital physics, will be discussed. This new mechanism frees up the usually difficult requirement of a two-body p-wave interaction or equivalent one. A new type of chiral p-wave superfluid state in two dimensions and a class of spatially modulated center-of-mass p-wave superfluids in quasi-one dimension are predicted for cold atom experimental detection, requiring only s-wave interaction. Secondly, our first prediction of Weyl superfluidity in dipolar cold gas systems will be introduced. The long-sought low-temperature analog of Weyl fermions of particle physics has been found in the quasi-particle excitations in this superfluid state. Such exotic excitations not only are important to understand high-energy/particle physics, but also play essential roles for fascinating transport properties in condensed matter physics. They are argued by many in the field to impact next-generation quantum technology.