Bias-voltage-controlled interlayer exchange coupling

摘要

The authors propose a new system whose magnetization direction can be controlled by an applied bias voltage without an external magnetic field. The system consists of a four layered structure F(sub 1)/S/I/F(sub 2) (F(sub 1)F(sub2): ferromagnets, S: spacer, I: insulator). An analytic expression for bias-voltage-controlled interlayer exchange coupling in this system is developed within a simple free-electron-like, one-dimensional approximation. According to the approach, the magnetic configurations of the two magnetic layers oscillate from antiferromagnetic to ferromagnetic with applied bias voltage. This implies that the authors can switch/rotate the magnetization direction without an external magnetic field. Possible applications of such a system are also discussed.