论文标题
稳定的液相液相
Stable pair liquid phase in fermionic systems
论文作者
论文摘要
我们预测具有有限范围有吸引力的相互作用的晶格费米亚系统中的配对相。这种异国情调的状态在一侧与未配对费米子的正常费米液体竞争，另一侧则具有相位分离状态，其中所有费米子都耦合到宏观簇中。我们表明，这种阶段在骨气系统中不存在，因此受到排除原理的保护。与零范围有吸引力的系统相反，该系统直接禁止了两个以上的费米子的聚类，量子统计数据以动态和更微妙的方式起作用。由于多屈光度波函数必须具有节点，因此群集的形成阈值大于配对形成阈值。通过直接在一维晶格上求解四体Schroedinger方程，我们映射了配对稳定性的边界。这对液相应在冷原子系统中观察到。我们还讨论了对高温超导性预先形成的配对机制的影响。
We predict the existence of a pair-liquid phase in lattice fermion systems with finite-range attractive interactions. This exotic state competes on one side with a normal Fermi liquid of unpaired fermions and on the other side with a phase-separated state where all fermions are coupled into macroscopic clusters. We show that such a phase is absent in bosonic systems and therefore is protected by the exclusion principle. In contrast with zero-range attractive systems where clustering of more than two fermions is directly prohibited, here quantum statistics acts dynamically and in a more subtle way. Since a many-fermion wave function must have nodes, the cluster formation threshold is larger than the pair formation threshold. By directly solving a four-body Schroedinger equation on one- and two-dimensional lattices, we map the boundaries of pair stability. The pair liquid phase should be observable in cold atom systems. We also discuss implications for the preformed-pair mechanism of high-temperature superconductivity.
