Departamento de Física de Materiales, Universidad Complutense de Madrid, E-28040 Madrid, Spain.
Phys Rev Lett. 2010 Aug 27;105(9):095301. doi: 10.1103/PhysRevLett.105.095301. Epub 2010 Aug 23.
We study a balanced two-component system of ultracold fermions in one dimension with attractive interactions and subject to a spin-dependent optical lattice potential of opposite sign for the two components. We find states with different types of modulated pairing order parameters which are conceptually similar to π phases discussed for superconductor-ferromagnet heterostructures. Increasing the lattice depth induces sharp transitions between states of different parity. While the origin of the order parameter oscillations is similar to the Fulde-Ferrel-Larkin-Ovchinnikov phase for paired states with spin imbalance, the current system is intrinsically stable to phase separation. We discuss experimental requirements for creating and probing these novel phases.
我们研究了一维中具有吸引力相互作用的冷原子双组份系统，并在两个组份上施加了一个具有相反符号的自旋相关光晶格势。我们发现了具有不同类型调制配对序参量的态，这些态在概念上类似于超导-铁磁异质结构中讨论的π 相。增加晶格深度会在不同宇称态之间产生急剧的转变。虽然有序参数振荡的起源类似于自旋不平衡配对态的富勒-费雷尔-拉金-奥夫钦尼科夫（Fulde-Ferrel-Larkin-Ovchinnikov，FFLO）相，但当前系统在本质上是稳定的，不会发生相分离。我们讨论了创造和探测这些新相的实验要求。
