Institut für Theorie der Statistischen Physik, RWTH Aachen University, 52056 Aachen, Germany.
J Phys Condens Matter. 2012 Oct 17;24(41):415301. doi: 10.1088/0953-8984/24/41/415301. Epub 2012 Sep 24.
We study the effect of Rashba spin-orbit interaction on the Josephson current through a double quantum dot in the presence of Coulomb repulsion. In particular, we describe the characteristic effects on the magnetic field-induced singlet-triplet transition in the molecular regime. Exploring the whole parameter space, we analyze the effects of the device asymmetry, the orientation of the applied magnetic field with respect to the spin-orbit interaction, and finite temperatures. We find that at finite temperatures the orthogonal component of the spin-orbit interaction exhibits a similar effect to the Coulomb interaction inducing the occurrence of a π-phase at particle-hole symmetry. This provides a new route to the experimental observability of the π-phase in multi-level quantum dots.
我们研究了 Rashba 自旋轨道相互作用对存在库仑排斥时通过双量子点的约瑟夫森电流的影响。特别是,我们描述了分子态中单态-三重态跃迁的磁场诱导的特征效应。通过探索整个参数空间,我们分析了器件不对称性、外加磁场相对于自旋轨道相互作用的方向以及有限温度的影响。我们发现,在有限温度下,自旋轨道相互作用的正交分量表现出与库仑相互作用类似的效果,导致在粒子空穴对称时出现π 相。这为在多能级量子点中实验观测到π 相提供了一种新途径。