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arXiv 2401.02259cond-mat.supr-conphysics.comp-ph
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单层NbSe2的最近邻配对促进拓扑超导态的出现

Nearest-Neighboring Pairing of Monolayer NbSe2 Facilitates the Emergence of Topological Superconducting States

Yizhi Li, Quan Gao, Yanru Li, Jianxin Zhong, Lijun Meng

AI总结:

本文基于紧束缚模型系统研究了单层NbSe2中混合在位s波与最近邻配对诱导的拓扑超导相,发现混合配对显著降低临界磁场并能在零磁场下实现可调制的拓扑超导态。

摘要:

NbSe2同时表现出超导性和自旋轨道耦合,有望为拓扑超导性和非常规电子配对铺平道路。本文基于紧束缚模型,通过混合在位s波配对(ps)与最近邻配对(psA1),系统研究了单层NbSe2中的拓扑超导(TSC)相。我们观察到丰富的相,其Chern数(CNs)根据化学势(μ)和面外磁场(Vz)的不同而表现出固定或敏感的特征。随着psA1的增加,TSC相根据是否存在体-边界对应关系(BBC)而表现出匹配和不匹配特征。引人注目的是,与纯s波配对相比,混合波配对的引入显著降低了形成TSC相的临界Vz。此外,在适当的μ和psA1下,即使在Vz=0时也可以调制TSC相,这通过带状结构的稳健拓扑边缘态(TESs)得到证实。此外,混合配对影响了体态和边缘态的杂化,导致在带状结构上出现具有局域/振荡TESs的匹配/不匹配BBC。我们的发现有助于在实验中实现TSC态,以及设计和调控TSC材料。

英文摘要:

NbSe2, which simultaneously exhibits superconductivity and spin-orbit coupling, is anticipated to pave the way for topological superconductivity and unconventional electron pairing. In this paper, we systematically study topological superconducting (TSC) phases in monolayer NbSe2 through mixing on-site s-wave pairing (ps) with nearest-neighbor pairing (psA1) based on a tight-binding model. We observe rich phases with both fixed and sensitive Chern numbers (CNs) depending on the chemical potential (μ) and out-of-plane magnetic field (Vz). As the psA1 increases, the TSC phase manifests matching and mismatching features according to whether there is a bulk-boundary correspondence (BBC). Strikingly, the introduction of mixed wave pairing significantly reduces the critical Vz to form TSC phases compared with the pure s-wave paring. Moreover, the TSC phase can be modulated even at Vz=0 under appropriate μ and psA1, which is identified by the robust topological edge states (TESs) of ribbons. Additionally, the mixed pairing influences the hybridization of bulk and edge states, resulting in a matching/mismatching BBC with localized/oscillating TESs on the ribbon. Our finding is helpful for the realization of TSC states in experiment, as well as designing and regulating TSC materials.

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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