论文标题
在定期驱动的SNS连接中，约瑟夫森二极管的非平衡二极管效应
Nonequilibrium Josephson diode effect in periodically driven SNS junctions
论文作者
论文摘要
在典型的约瑟夫森连接中，约瑟夫森电流是超导相位差的奇数函数。最近，在Josephson连接中的二极管效应在实验中观察到了Josephson电流的最大值和最小值，在电流相关关系中的最小值和最小值没有相同的幅度。我们提出了一个超导体非正式金属螺旋体（SNS）结，在驱动正常金属区域时，约瑟夫森二极管效应表现出来。时间逆转对称性和反转对称性需要在SNS连接中打破以显示二极管效应。我们计算了长时间的平均电流，并表明该系统对驱动的SNS连接的两种配置表现出二极管效应 - 一种在Hamiltonian的未经传动部分中损坏了反转对称性，而另一种对称对称性则因驱动势而破坏。在后一种构型中，在没有相位偏置的情况下，被称为异常电流的非零电流出现在结处。在拟议的设置中，二极管效应在绝热极限中消失。
In typical Josephson junctions, the Josephson current is an odd function of the superconducting phase difference. Recently, diode effect in Josephson junctions is observed in experiments wherein the maximum and the minimum values of the Josephson current in the current-phase relation do not have the same magnitude. We propose a superconductor-normal metal-superconductor (SNS) junction where Josephson diode effect manifests when the normal metal region is driven. Time reversal symmetry and inversion symmetry need to be broken in the SNS junction for the diode effect to show up. We calculate long time averaged current and show that the system exhibits diode effect for two configurations of the driven SNS junction - one in which inversion symmetry is broken in the undriven part of the Hamiltonian and the other wherein both the symmetries are broken by the driving potential. In the latter configuration, a nonzero current known as anomalous current appears at the junction in absence of phase bias. In the proposed setup, the diode effect vanishes in the adiabatic limit.
