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arXiv 2008.09823cond-mat.supr-concond-mat.mes-hallcond-mat.str-el
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超导点接触的非弹道输运特性

Non-ballistic transport characteristics of superconducting point-contacts

Ritesh Kumar, Goutam Sheet

摘要:

在“弹道”机制中,通过正常金属(N)/超导体(S)点接触的输运由称为Andreev反射的量子过程主导。Andreev反射导致超导能隙以下电导的增强,并且当超导体本质上是常规超导体时,低偏压电导与高偏压电导的比率不能大于2。在这种情况下,与Andreev反射相关的特征也提供了关于超导相的能量和动量分辨光谱信息。在这里,我们从理论上考虑各种类型的N/S点接触,远离弹道制度,并表明,即使当所调查的超导体是简单的传统性质,根据形状,大小和解剖的点接触,各种各样的光谱特征可能会出现在电导谱。这些特征可能会误导性地模仿理论上预期的奇异物理现象的特征,如拓扑超导体中的克莱因隧穿,非常规超导体中的Andreev束缚态,多带超导性和Majorana零模式。

英文摘要:

In the "ballistic" regime, the transport across a normal metal (N)/superconductor (S) point-contact is dominated by a quantum process called Andreev reflection. Andreev reflection causes an enhancement of the conductance below the superconducting energy gap, and the ratio of the low-bias and the high-bias conductance cannot be greater than 2 when the superconductor is conventional in nature. In this regime, the features associated with Andreev reflection also provide energy and momentum-resolved spectroscopic information about the superconducting phase. Here we theoretically consider various types of N/S point contacts, away from the ballistic regime, and show that even when the superconductor under investigation is simple conventional in nature, depending on the shape, size and anatomy of the point contacts, a wide variety of spectral features may appear in the conductance spectra. Such features may misleadingly mimic theoretically expected signatures of exotic physical phenomena like Klein tunneling in topological superconductors, Andreev bound states in unconventional superconductors, multiband superconductivity and Majorana zero modes.

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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