Cai Xiaoming
State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China.
J Phys Condens Matter. 2017 Mar 22;29(11):115401. doi: 10.1088/1361-648X/aa5a39. Epub 2017 Jan 18.
We study the competition of disorder and superconductivity for a generalized Kitaev model in incommensurate potentials. The generalized Kitaev model describes one dimensional spinless fermions with long-range p-wave superconducting pairing, which decays with distance l as a power law ∼[Formula: see text]. We focus on the transition from the topological superconducting phase to the topologically trivial Anderson localized phase, and effects of the exponent α on this phase transition. In the topological superconducting phase, for a system under open boundary condition the amplitude of zero-mode Majorana fermion has a hybrid exponential-algebraic decay as the distance increases from the edge. In the Anderson localized phase, some single-particle states remain critical for very strong disorders and the number of critical states increases as α decreases. In addition, except for critical disorders, the correlation function always has an exponential decay at the short range and an algebraic decay at the long range. Phase transition points are also numerically determined and the topological phase transition happens earlier at a smaller disorder strength for a system with smaller α.
我们研究了在非 commensurate 势中广义 Kitaev 模型的无序与超导之间的竞争。广义 Kitaev 模型描述了具有长程 p 波超导配对的一维无自旋费米子，其随距离 l 以幂律 ∼[公式：见文本] 衰减。我们关注从拓扑超导相到拓扑平凡的安德森局域相的转变，以及指数 α 对该相变的影响。在拓扑超导相中，对于处于开放边界条件下的系统，零模马约拉纳费米子的振幅随着从边缘起距离的增加呈现混合指数 - 代数衰减。在安德森局域相中，一些单粒子态对于非常强的无序仍保持临界状态，并且临界态的数量随着 α 的减小而增加。此外，除了临界无序外，关联函数在短程总是具有指数衰减，而在长程具有代数衰减。还通过数值确定了相变点，并且对于具有较小 α 的系统，拓扑相变在较小的无序强度下更早发生。
