Takagaki Y
Paul-Drude-Institut für Festkörperelektronik, Leibniz-Institut im Forschungsverbund Berlin e. V., Hausvogteiplatz 5-7, 10117 Berlin, Germany.
J Phys Condens Matter. 2019 Dec 4;31(48):485301. doi: 10.1088/1361-648X/ab3aa5. Epub 2019 Aug 13.
Magnetic-field dependence of the transport properties of ballistic two-dimensional electrons in a planar superconductor-normal-conductor-superconductor structure is numerically investigated. In the circumstance where the Andreev reflection from the normal-conductor-superconductor interfaces is almost perfect, two oscillatory behaviors occur for magnetic fields higher and lower than that for the coincidence of the cyclotron diameter with the separation between the superconductors. The oscillation period for the former and latter cases is proportional to the magnetic field and inverse of the magnetic field, respectively. The low-field oscillation originates from commensurability-driven guiding of Andreev-reflected trajectories along the interfaces between the normal conductor and the superconductors. If the Andreev reflection probability is considerably less than unity, the commensurability oscillation is suppressed in amplitude and is dwarfed by additionally emerged oscillations originating from the quantum interference between the Andreev- and normal-reflected components.
对平面超导体 - 正常导体 - 超导体结构中弹道二维电子输运性质的磁场依赖性进行了数值研究。在正常导体 - 超导体界面处的安德列夫反射几乎完美的情况下，对于高于和低于回旋直径与超导体之间间距重合时的磁场，会出现两种振荡行为。前一种情况和后一种情况的振荡周期分别与磁场成正比和与磁场成反比。低场振荡源于沿正常导体与超导体之间界面的安德列夫反射轨迹的可公度性驱动引导。如果安德列夫反射概率远小于1，可公度性振荡的幅度会受到抑制，并与源于安德列夫反射分量和正常反射分量之间量子干涉的额外出现的振荡相比显得微不足道。
