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arXiv 2210.05024cond-mat.str-elcond-mat.mes-hallcond-mat.supr-conmath-phmath.MP
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相互作用一维超导体中的分数拓扑

Fractional Topology in Interacting 1D Superconductors

Frederick del Pozo, Loïc Herviou, Karyn Le Hur

AI总结:

本研究探究一维相互作用超导纳米线的拓扑相,提出可直接测量的拓扑标记,证实DCI相为分数拓扑相,还揭示了线间跳跃振幅对相图、拓扑相及有序态的调控规律。

摘要:

我们研究了两条一维(1D)相互作用超导纳米线的拓扑相,并提出了可通过基态关联函数直接测量的拓扑标记。这些物理量在存在耦合和相互作用的情况下依然是有效的研究工具。我们通过密度矩阵重整化群证明,文献[1]中发现的双临界伊辛(DCI)相是一种分数拓扑相,其体相中存在无能隙Majorana模,且每条纳米线对应二分之一的拓扑不变量。结合数值计算与量子场论方法,我们发现在线间跳跃振幅$t_{\bot}$存在时,长度尺度小于$\boldsymbol{\rm{\textbf{~}}}1/t_{\bot}$的范围内相图保持稳定。较大的线间跳跃振幅会催生两个整数拓扑相,它们在强相互作用下也能保持稳定,且在两条纳米线共有的每个边界上存在一个边缘模。在强相互作用下,两条纳米线由Mott物理描述,此时$t_{\bot}$跳跃振幅会导致顺磁有序。

英文摘要:

We investigate the topological phases of two one-dimensional (1D) interacting superconducting wires and propose topological markers directly measurable from ground state correlation functions. These quantities remain powerful tools in the presence of couplings and interactions. We show with the density matrix renormalization group that the double critical Ising (DCI) phase discovered in [1] is a fractional topological phase with gapless Majorana modes in the bulk, and a one-half topological invariant per wire. Using both numerics and quantum field theoretical methods, we show that the phase diagram remains stable in the presence of an inter-wire hopping amplitude $t_{\bot}$ at length scales below $\sim 1/t_{\bot}$. A large inter-wire hopping amplitude results in the emergence of two integer topological phases, stable also at large interactions. They host one edge mode per boundary shared between both wires. At large interactions, the two wires are described by Mott physics, with the $t_{\bot}$ hopping amplitude resulting in a paramagnetic order.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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