Yamamoto Daisuke, Spielman I B, Sá de Melo C A R
Department of Physics and Mathematics, Aoyama-Gakuin University, Sagamihara, Kanagawa 252-5258, Japan.
Joint Quantum Institute, National Institute of Standards and Technology, and University of Maryland, Gaithersburg, Maryland 20899, USA.
Phys Rev A (Coll Park). 2017 Dec;96(6). doi: 10.1103/PhysRevA.96.061603. Epub 2017 Dec 26.
Ultracold bosons in optical lattices are one of the few systems where bosonic matter is known to exhibit strong correlations. Here we push the frontier of our understanding of interacting bosons in optical lattices by adding synthetic spin-orbit coupling, and show that new kinds of density- and chiral-orders develop. The competition between the optical lattice period and the spin-orbit coupling length - which can be made comparable in experiments - along with the spin hybridization induced by a transverse field (i.e., Rabi coupling) and interparticle interactions create a rich variety of quantum phases including uniform, non-uniform and phase-separated superfluids, as well as Mott insulators. The spontaneous symmetry breaking phenomena at the transitions between them are explained by a two-order-parameter Ginzburg-Landau model with multiparticle umklapp processes. Finally, in order to characterize each phase, we calculated their experimentally measurable crystal momentum distributions. PACS numbers: 67.85.-d,67.85.Hj,67.85.Fg.
光学晶格中的超冷玻色子是已知的少数几个玻色子物质表现出强关联的系统之一。在此，我们通过添加合成自旋轨道耦合来拓展对光学晶格中相互作用玻色子的理解前沿，并表明会形成新型的密度序和手征序。光学晶格周期与自旋轨道耦合长度之间的竞争（在实验中可使其具有可比性），以及由横向场诱导的自旋杂化（即拉比耦合）和粒子间相互作用，创造了丰富多样的量子相，包括均匀、非均匀和相分离的超流体，以及莫特绝缘体。它们之间转变时的自发对称破缺现象由具有多粒子倒格矢过程的双序参量金兹堡 - 朗道模型来解释。最后，为了表征每个相，我们计算了它们实验上可测量的晶体动量分布。物理评论快报分类号：67.85.-d，67.85.Hj，67.85.Fg。
