Voltage-Controlled Magnonic Spin Tunneling Junction

We theoretically investigate the effective exchange interaction, J_eff, mediated by conductive electrons within a nonmagnetic metal spacer, in the presence of a bias voltage, sandwiched by two ferromagnetic insulators. On the basis of the tight-binding model, we show the voltage and spacer thickness dependences of J_eff, and its contorollability is demonstrated. We also propose a new magnonic device with the functions of both field effect transistor and nonvolatile memory.