Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble, France.
Phys Rev Lett. 2009 Dec 11;103(24):247002. doi: 10.1103/PhysRevLett.103.247002. Epub 2009 Dec 8.
We construct a theory of coherent transport through a ballistic quantum dot coupled to a superconductor. We show that the leading-order quantum correction to the two-terminal conductance of these Andreev quantum dots may change sign depending on (i) the number of channels carried by the normal leads or (ii) the magnetic flux threading the dot. In contrast, spin-orbit interaction may affect the magnitude of the correction, but not always its sign. Experimental signatures of the effect include a nonmonotonic magnetoconductance curve and a transition from an insulator-like to a metal-like temperature dependence of the conductance. Our results are applicable to ballistic or disordered dots.
我们构建了一个超导量子点与弹道量子点耦合的相干输运理论。我们表明，这些安德烈夫量子点的两端电导的一阶量子修正可能会根据（i）正常引线携带的通道数量或（ii）穿过点的磁通量而改变符号。相比之下，自旋轨道相互作用可能会影响修正的幅度，但不一定会改变其符号。这种效应的实验特征包括非单调磁导率曲线以及从类似绝缘体到类似金属的电导温度依赖性的转变。我们的结果适用于弹道或无序点。
