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arXiv 0802.2055cond-mat.mes-hallcond-mat.supr-con
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超导体-石墨烯纳米结构邻近效应的微观理论

Microscopic theory of the proximity effect in superconductor-graphene nanostructures

P. Burset, A. L. Yeyati, A. Martín-Rodero

摘要:

本文对石墨烯-超导体界面的邻近效应进行了理论分析。我们使用紧束缚模型的电子状态在这个系统中,它允许在微观水平上描述的接口。提出了两种不同的界面模型:一种是超导体在下面的石墨烯区域中诱导有限配对,从而保持界面处的蜂窝结构,另一种是假设石墨烯层直接耦合到块状超导电极。我们发现,像Andreev反射概率和它的通道分解的属性严重依赖于用于描述接口的模型。我们还研究了邻近效应对石墨烯局域态密度的影响。对于有限层,我们分析了诱导的minigap和它是如何减少时,层的长度增加。有限和半无限层的局部状态分布密度的结果。

英文摘要:

We present a theoretical analysis of the proximity effect at a graphene-superconductor interface. We use a tight-binding model for the electronic states in this system which allows to describe the interface at the microscopic level. Two different interface models are proposed: one in which the superconductor induces a finite pairing in the graphene regions underneath, thus maintaining the honeycomb structure at the interface and one that assumes that the graphene layer is directly coupled to a bulk superconducting electrode. We show that properties like the Andreev reflection probability and its channel decomposition depend critically on the model used to describe the interface. We also study the proximity effect on the local density of states on the graphene. For finite layers we analyze the induced minigap and how it is reduced when the length of the layer increases. Results for the local density of states profiles for finite and semi-infinite layers are presented.

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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