Spin density induced by equilibrium spin current in a magnetic field

Abstract

We propose theoretically to use an external magnetic field to detect the equilibriumspin current which flows in a narrow strip. The spin current is generated by twononcollinear ferromagnets attached to the strip and the applied magnetic field isperpendicular to the plane of the strip. It is demonstrated by using the KeldyshGreen’s function that the interaction between the spin current and the magneticfield causes an antisymmetrical spin density at the two lateral edges of the strip.The spin density can be directly measured experimentally. Its magnitude anddirection can be readily controlled by the magnetizations of the ferromagnets. Theproposed scheme offers a new approach to the detection of the pure spin current.