Prediction of switching rotation of the magnetization direction with applied voltage in a controllable interlayer exchange coupled system

We propose a ferromagnetic/spacer/insulator/ferromagnetic system whose magnetization direction can be controlled by an applied bias voltage. An analytic expression for controllable exchange coupling in this system is shown within a simple free-electron-like, one-dimensional approximation. According to the approach, the magnetic configurations of two magnetic layers oscillate from antiferromagnetic to ferromagnetic with applied bias voltage. This implies that we can switch/rotate the magnetization direction without an external magnetic field. Possible applications of such a system are discussed. (C) 1999 Elsevier Science B.V. All rights reserved.