Voltage control of magnon spin currents in an antiferromagnetic insulator

Abstract

Voltage-controlled spintronic devices utilizing the spin degree of freedom are desirable for future applications, and may allow energy-efficient information processing. A pure spin current can be created by thermal excitations in magnetic systems via the spin Seebeck effect (SSE). However, controlling such spin currents, by purely electrical means, has been a fundamental challenge. Here, we investigate voltage control of the SSE in an antiferromagnetic insulator. We demonstrate that the SSE response generated in this material can be effectively controlled by applying a bias voltage, owing to the sensitivity of the SSE to the orientation of the magnetic sublattices as well as the existence of magnetoelectric couplings in the present system. Our experimental results on the voltage-controlled switching of magnetic sublattices are explained using a model based on the magnetoelectric effect. Acknowledgments: all work at Argonne was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. The use of facilities at the Center for Nanoscale Materials, an Office of Science user facility, was supported by the US Department of Energy, Basic Energy Sciences under Contract No. DE-AC02-06CH11357.