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arXiv 1105.2600cond-mat.mes-hall
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石墨烯平面结的约瑟夫森电流

Josephson Current through a Planar Junction of Graphene

Yositake Takane, Ken-Ichiro Imura

摘要:

通过假设石墨烯片与其上两个超导体的耦合用隧穿哈密顿量描述,研究了平面石墨烯结中的约瑟夫森效应。该模型适当地考虑了平面结的邻近效应特性,并允许我们以平行的方式处理单层和双层的情况。应用准经典格林函数方法分析了短结极限下的约瑟夫森临界电流$I_{\rm c}$。作为平面结的一个特征,我们发现在强耦合极限下,$I_{\rm c}$是温度的凹函数,而随着耦合强度的降低,它转变为凸函数。我们还发现不同的化学势依赖性的$I_{\rm c}$在单层和双层的情况下。

英文摘要:

Josephson effect in a planar graphene junction is studied by assuming that the coupling of a graphene sheet and two superconductors deposited on its top is described by a tunneling Hamiltonian. This model properly takes account of the proximity effect characteristic to a planar junction, and allows us to treat monolayer and bilayer cases in a parallel manner. Applying a quasiclassical Green's function approach to it we analyze the Josephson critical current $I_{\rm c}$ in a short-junction limit. As a characteristic feature of the planar junction we find that $I_{\rm c}$ is a concave function of temperature at the strong coupling limit while it crosses over to a convex function with decreasing the coupling strength. We also find different chemical-potential dependences of $I_{\rm c}$ in the monolayer and bilayer cases.

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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