Spin-orbit coupling effects on the superfluidity of a Fermi gas in an optical lattice
Spin-orbit coupling effects on the superfluidity of a Fermi gas in an optical lattice
复制标题
自旋轨道耦合对光学晶格中费米气体超流性的影响
DOI：
10.1103/physreva.88.063637
复制
发表时间：
2013-04
影响因子：
2.9
通讯作者：
A.-C. Ji
中科院分区：
文献类型：
--
作者：
Q. Sun;G.-B. Zhu;W.-M. Liu;A.-C. Ji
研究了自旋轨道耦合正方形光学晶格中吸引费米气体的超流性。我们表明，该系统显示了各种新的功能。在半充满时，SOC诱导狄拉克半金属，系统经历半金属-超流转变。在接近半满时，我们发现由于狄拉克锥的出现，超流性趋于被抑制。而对于小填充，SOC可以诱导BCS-BEC交叉超出传统的吸引力Hubbard模型，其特征在于在晶格中的束缚态。此外，我们证明了超流密度在晶格中也表现出许多不寻常的性质。
We investigate the superfluidity of attractive Fermi gas in a square optical lattice with spin-orbit coupling (SOC). We show that the system displays a variety of new features. At half filling, SOC induces a Dirac semimetal and the system undergoes a semimetal-superfluid transition. Near half filling, we find that the superfluidity tends to be suppressed due to the emerging Dirac cones. While for small fillings, SOC can induce a BCS-BEC crossover beyond the conventional attractive Hubbard model, which is characterized by a bound state in the lattices. Moreover, we demonstrate that the superfluid density also exhibits many unusual properties in the lattices.