Giant Edelstein effect in the surface states of non-centrosymmetric superconductors

It is an important topic in the modern field of spintronics to control magnetic moments by using local electric current. One of the representative methods is the Edelstein effect [1]. However, for practical applications, e.g. magnetic domain switching [2], it is widely known that quite a large amount of electric current density is needed. Therefore, Joule heating created by a dissipative current is the main obstacle for efficient control of magnetization.
In this study, we theoretically demonstrate that the edge state of a non-centrosymmetric superconductor is a good candidate for efficient magnetization control. By using tight-binding calculations, we have found that, in d-wave superconductors, the coefficient of the magneto-electric effect in the edge state is about eighty times larger than in the bulk state. We also have found that its topological winding number is the key factor of this giant Edelstein effect.


[1] V. M. Edelstein, Phys. Rev. Lett. 75, 2004 (1995).
[2] I. M. Miron et al., Nature Materials 9, 230-234 (2010).