中国科学院武汉物理与数学研究所

报告人简介：

江开军，中国科学院武汉物理与数学研究所研究员，博士生导师。1994～1998，武汉大学获学士学位；1999～2005，中科院武汉物理与数学研究所(WIPM)获博士学位；2005～2008，美国国家标准与技术研究院(NIST)从事博士后研究；2008～2010，法国巴黎高等师范学院(ENS)从事博士后研究；2010～至今，中科院武汉物理与数学研究所任研究员。从事超冷原子物理研究，发表SCI论文30余篇，包括1篇Nature和5篇PRL等。现主要研究方向：简并费米气体中的少体和多体相互作用；具有球对称玻色凝聚体的集体行为和自旋-轨道角动量耦合玻色气体的新奇量子态。

报告摘要：

Coupling between particle's spin and orbital motion is ubiquitous in atoms, photons, solid materials and many other systems. It contributes to the topological properties like quantum-Hall effect in solid materials and electronic fine structure in atoms. Ultracold atoms with a high tunability provides an ideal platform to study spin-orbit (SO) coupling. Spin-linear-momentum (SLM) coupling has been observed in quantum gases and subsequently a variety of exotic quantum states have been explored. While the experimental study on the other kind of SO coupling, namely the spin-orbital-angular-momentum (SOAM) coupling, is still lacking.

In this talk, I will report the experimental observation of the ground-state phase diagram of the SOAM coupled Bose-Einstein condensate. By inducing a Raman transition using a pair of Gaussian and Laguerre-Gaussian (LG) laser beams, we realize SOAM coupling of ultracold atoms. We observe phase transitions when the two-photon Raman coupling strength or detuning approaches the critical value. The phase transitions are classified as the first order, which feature a discontinuous jump of the angular momentum (OAM) and the spin polarization. We demonstrate the hysteresis loop across the first-order phase transition. The role of interatomic interaction on the phase transition is also elucidated.

邀 请 人：刘伍明（电话：8264 9249）

联 系 人：李园园（电话：8264 9364）