正常金属-铁磁绝缘层-dx2-y2+idxy混合波超导结中的磁散射对隧道谱的影响

在正常金属铁磁绝缘层dx2-y2 idxy混合波超导隧道结中,考虑到铁磁绝缘层的磁散射和界面的粗糙散射效应,运用BogoliubovdeGennes(BdG)方程和BlonderTinkhamKlapwijk(BTK)理论,计算了隧道结中的准粒子传输系数和微分电导.研究表明:(1)磁散射和界面粗糙散射均可以压低电导峰,其中磁散射能使电导峰滑移,而粗糙界面散射却能阻止这种滑移,且两散射的共同作用可抑制由混合波两序参数的幅值比不同所导致的电导峰滑移;(2)随铁磁层离超导表面距离的增加,隧道谱在零偏压处由凹陷变成了零偏压电导峰,继而又演化为凹陷中的中心峰;(3)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级谐振峰.

MAGNETIC SCATTERING EFFECT ON THE TUNNELING SPECTRA IN THE NORMAL METAL-FERROMAGNET INSULATOR- d x2-y2+id xy MIXED WAVE SUPERCONDUCTOR JUNCTIONS

Taking into account the magnetic scattering and rough interface scattering effects of the ferromagnet layer in the normal metal-ferromagnet insulator-d__ x2-y2 id_ xy mixed wave superconductor tunnel junctions,using Bogoliubov-de Gennes(BdG) eguation and Blonder-Tinkham-klapwjrk(BTK)theory, We calculate the quasiparticle transport coefficients and the differential conductance. It is found that: (1)both magnetic scattering and rough interface scattering can abate the conductance peaks, in which the magnetic scattering can lead to a splitting of the peaks but the rough interface scattering can resist the splitting,and the joint effect of two scattering may suppress the splitting of the conductance peaks that are caused by the different magnitude ratio of two order parameter of mixed wave; (2)with increasing of the distance of the ferromagnet layer away from the superconductor interface,the tunneling spectra at zero-bias are changed from the dips to the peaks, then evolve the central peaks in the dips; (3)the energy level resonant peaks in the tunneling spectra are predicted if the ferromagnet layer is located several superconductor coherence lengths away from the superconductor interface.