标题： 短球形石墨烯结中的次谐波间隙结构 显示英文标题

标题： Subharmonic gap structure in short ballistic graphene junctions

摘要： 我们对弹道超导体-正常态-超导体（SNS）结的电流-电压特性进行了理论分析，其中石墨烯条带与两个超导电极耦合。 我们关注短结区域，在该区域内，条带的长度远小于超导相干长度。 我们表明，微分电导表现出非常丰富的次谐波间隙结构，可以通过栅极电压进行调制。 在接近狄拉克点时，归一化为正常态电导的电导与短扩散SNS结的电导相同。 显示英文摘要

摘要： We present a theoretical analysis of the current-voltage characteristics of a ballistic superconductor-normal-superconductor (SNS) junction, in which a strip of graphene is coupled to two superconducting electrodes. We focus in the short-junction regime, where the length of the strip is much smaller than superconducting coherence length. We show that the differential conductance exhibits a very rich subharmonic gap structure which can be modulated by means of a gate voltage. On approaching the Dirac point the conductance normalized by the normal-state conductance is identical to that of a short diffusive SNS junction.