Stretching magnetism with an electric field in a nitride semiconductor

TL;DR

This study demonstrates electrical control of magnetization in (Ga,Mn)N using a new detection scheme, linking piezoelectric effects to magnetic anisotropy changes with a quantitative theory.

Contribution

It introduces a novel experimental detection method and develops a theory explaining electric field-induced magnetization changes in (Ga,Mn)N without adjustable parameters.

Findings

Magnetization can be controlled by electric fields up to 5 MV/cm.

The developed theory accurately predicts magnetization dependence on electric field, magnetic field, and temperature.

The work connects piezoelectricity with magnetoelectric effects in wurtzite semiconductors.

Abstract

By direct magnetization measurements, performed employing a new detection scheme, we demonstrate an electrical control of magnetization in wurtzite (Ga,Mn)N. In this dilute magnetic insulator the Fermi energy is pinned by Mn ions in the mid-gap region, and the Mn3+ ions show strong single-ion anisotropy. We establish that (Ga,Mn)N sustains an electric field up to at least 5 MV/cm, indicating that Mn doping turns GaN into a worthwhile semi-insulating material. Under these conditions, the magnetoelectric coupling may be driven by the inverse piezoelectric effect that stretches the elementary cell along the c axis and, thus, affects the magnitude of magnetic anisotropy. We develop a corresponding theory and show that it describes the experimentally determined dependence of magnetization on the electric field quantitatively with no adjustable parameters as a function of the magnetic field and temperature. In this way, our work bridges two research domains developed so far independently: piezoelectricity of wurtzite semiconductors and electrical control of magnetization in hybrid and composite magnetic structures containing piezoelectric components.