Xu Zhi-Fang, Li Xiaopeng, Zoller Peter, Liu W Vincent
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA.
Phys Rev Lett. 2015 Mar 27;114(12):125303. doi: 10.1103/PhysRevLett.114.125303.
We study a mixture of spin-1 bosonic and spin-1/2 fermionic cold atoms, e.g., ^{87}Rb and ^{6}Li, confined in a triangular optical lattice. With fermions at 3/4 filling, Fermi surface nesting leads to spontaneous formation of various spin textures of bosons in the ground state, such as collinear, coplanar, and even noncoplanar spin orders. The phase diagram is mapped out with varying boson tunneling and Bose-Fermi interactions. Most significantly, in one noncoplanar state the mixture is found to exhibit a spontaneous quantum Hall effect in fermions and crystalline superfluidity in bosons, both driven by interaction.
我们研究了被限制在三角形光学晶格中的自旋为1的玻色子和自旋为1/2的费米子冷原子的混合物，例如(^{87}Rb)和(^{6}Li)。在费米子填充率为3/4时，费米面嵌套导致基态玻色子自发形成各种自旋纹理，如共线、共面甚至非共面自旋序。通过改变玻色子隧穿和玻色 - 费米相互作用绘制出相图。最显著的是，在一种非共面状态下，发现该混合物在费米子中表现出自发量子霍尔效应，在玻色子中表现出晶体超流性，两者均由相互作用驱动。
