正常金属─铁磁绝缘层─S波超导结中的磁散射对量子输运的影响

Magnetic Scattering Effect on Quantum Transport in a Normal-Metal-Ferromagnet Insulator-S-Wave Superconductor Junctions

】在正常金属铁磁绝缘层Ｓ波超导隧道结中，考虑到铁磁层的磁散射和粗糙界面散射，运用Ｂｏｇｏｌｉｕｂｏｖ－ｄｅ－Ｇｅｎｎｅｓ（ＢｄＧ）方程和Ｂｌｏｎｄｅｒ－Ｔｉｎｋｈａｍ－Ｋｌａｐｗｉｊｋ（ＢＴＫ）理论模型，计算隧道结中的准粒子输运系数和微分电导。计算表明：（１）粗糙界面散射和磁散射都能使能隙电导峰变低、零能凹陷升高，随着两散射逐渐增强，还可使能隙峰变为凹陷，零能凹陷变为宽峰；（２）当铁磁层离开超导表面有若干相干长度时，隧道谱中将呈现一些子能隙谐振峰。

Taking into account rough interface scattering and magnetic scattering effect of the ferromagnet layer in the normal-metal-ferromagnet insulate-s-wave superconductor junctions,using Bogoliubov-de-Gennes (BdG) equation and Blonder-Tinkham-Klapwijk (BTK) model,we calculate the quasiparticle transport coefficients and the differential conductance.It is found that (1) both rough interface scattering and magnetic scattering can suppress the peaks at energy gap and raise the dips at zero-energy,and with increasing of two scattering,the peaks at energy gap will evolve the dips,the dips at zero-energy will evolve the peaks;(2) the subgap resonances in the differential conductance are predicted if the ferromagnet layer is located several superconductor coherence lengths away from the superconductor interface.