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arXiv 0704.2487cond-mat.mes-hallcond-mat.supr-con
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石墨烯n-pn结与超导体耦合的再进入效应

Reentrance effect in a graphene n-p-n junction coupled to a superconductor

A. Ossipov, M. Titov, C. W. J. Beenakker

摘要:

我们研究了石墨烯中n掺杂和p掺杂区域之间的Klein隧穿(=带间隧穿)和超导电极上的Andreev反射(=电子-空穴转换)的相互作用。当温度降低时,n-pn结的隧穿电导最初增加,而电子-空穴对的相干时间仍然小于它们的寿命,但是当相干时间超过寿命时,隧穿电导再次下降。从扩散导体和弹道量子点已知的这种再入效应提供了一种检测电子-空穴对的相位相干克莱因隧穿的方法。

英文摘要:

We study the interplay of Klein tunneling (= interband tunneling) between n-doped and p-doped regions in graphene and Andreev reflection (= electron-hole conversion) at a superconducting electrode. The tunneling conductance of an n-p-n junction initially increases upon lowering the temperature, while the coherence time of the electron-hole pairs is still less than their lifetime, but then drops back again when the coherence time exceeds the lifetime. This reentrance effect, known from diffusive conductors and ballistic quantum dots, provides a method to detect phase coherent Klein tunneling of electron-hole pairs.

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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