石墨烯铁磁-绝缘层-超导结的输运

本文运用平均场模型的Dirac-Bogoliubov-de-Gennes方程和Bolonder-Tinkham-Klapwijk理论研究石墨烯铁磁-绝缘层-超导结的输运性质.研究表明:考虑有限宽度的绝缘层,隧穿电导-电压曲线呈现无衰减的振荡行为;同时隧穿电导随铁磁层中的交换能呈现非单调变化.对上述现象从石墨烯中类Dirac准粒子色散关系密切相关的电子散射过程予以解释.

Tunneling conductance sp ectrum of graphene ferromagnet-insulator-sup erconductor junctions

Starting with the mean field Dirac-Bogoliubov-de-Gennes model and the Bolonder-Tinkham-Klapwijk formalism, we study the transport properties of a graphene ferromagnet-insulator-superconductor junction by taking into account the effect of the finite width of the insulating region. The tunneling conductance oscillations as a function of the bias energy are revealed together with a non-monotonic behavior for the exchange field in the ferromagnet layer. These phenomena, which are quite different from those in the conventional counterparts, are understood by examining the electron scattering processes associated with the unique dispersion-relation of the graphene junctions.
Keywords：graphene junctiontunneling conductanceexchange energyosicllation spectum