Phase diagram of a non-Abelian Aubry-André-Harper model with p -wave superfluidity
Phase diagram of a non-Abelian Aubry-André-Harper model with p -wave superfluidity
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DOI：
10.1103/physrevb.93.104504
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发表时间：
2015-05
影响因子：
3.7
通讯作者：
Jun Wang;Xiaji Liu;Xianlong Gao;Hui Hu
中科院分区：
文献类型：
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作者：
Jun Wang;Xiaji Liu;Xianlong Gao;Hui Hu
本文从均匀磁场中正方形晶格上的拓扑非平凡紧束缚模型出发，在非阿贝尔规范场作用下，研究了一维准周期费米系统的拓扑p波超流性.该系统可以被认为是著名的Aubry-Andr\'e-Harper模型的非阿贝尔推广。我们调查其相图作为准无序的强度和振幅的$p$波序参数的函数，通过一些数值调查，包括多重分形分析。有四个不同的阶段由三条关键线分开，即，两个阶段与所有扩展的波函数（I和IV），拓扑平凡阶段（II）与所有本地化的波函数和临界阶段（III）与所有多重分形波函数。第一阶段与第四阶段通过对偶性相关联。它似乎也与第二阶段的二元性有关。考虑到用超冷原子模拟非阿贝尔规范场和拓扑绝缘体/超流体，我们提出的相图可以在当前的冷原子实验中观察到。
We theoretically study a one-dimensional quasi-periodic Fermi system with topological $p$-wave superfluidity, which can be deduced from a topologically non-trivial tight-binding model on the square lattice in a uniform magnetic field and subject to a non-Abelian gauge field. The system may be regarded a non-Abelian generalization of the well-known Aubry-Andr\'e-Harper model. We investigate its phase diagram as functions of the strength of the quasi-disorder and the amplitude of the $p$-wave order parameter, through a number of numerical investigations, including a multifractal analysis. There are four distinct phases separated by three critical lines, i.e., two phases with all extended wave-functions (I and IV), a topologically trivial phase (II) with all localized wave-functions and a critical phase (III) with all multifractal wave-functions. The phase I is related to the phase IV by duality. It also seems to be related to the phase II by duality. Our proposed phase diagram may be observable in current cold-atom experiments, in view of simulating non-Abelian gauge fields and topological insulators/superfluids with ultracold atoms.