磁性d波超导/铁磁/磁性d波超导结中的约瑟夫森效应

Josephson effect in ferromagnetic d-wave superconductor/ferromagnet/ferromagnetic d-wave superconductor junctions

通过求解磁性d波超导中的能隙和磁交换能的自洽方程,研究磁性d波超导/铁磁/磁性d波超导结中的约瑟夫森电流.计算结果表明:1)临界电流随中间的铁磁层厚度呈现出两种不同周期的振荡混合,通过增强铁磁层中的磁交换能q0和铁磁/磁性d波超导界面处的势垒强度z0,短周期分量可从长周期中分离出来,反之,通过降低q0和z0,长周期分量可从短周期中分离出来;2)在两边磁性d波超导的磁化方向取平行时,在取一些特定的铁磁层厚度下,磁性d波超导中的磁交换能可增强系统的临界电流.

By solving a self-consistent equation for the ferromagnetic d-wave superconducting gap and the exchange energy, we study the Josephson current in the ferromagnetic d-wave superconductor/ferromagnet/ferromagnetic d-wave superconductor junctions. In the Josephson critical current, there are two oscillation components with different periods. It is found that the short-period component can be separated from the long-period one by increasing the exchange energy in ferromagnet and the barrier strength at the ferromag- net/ferromagnetic d-wave superconductor interface, and vice versa. Under a certain thickness for the ferromagnet, exchange energy for the ferromagnetic d-wave superconductor may increase the critical current in the case of a parallel alignment of the magnetization in the ferromagnetic d-wave superconductor.