Carrier-mediated magnetoelectricity in complex oxide heterostructures

TL;DR

This paper introduces a universal carrier-mediated magnetoelectric effect at dielectric-metal interfaces, demonstrated through first-principles calculations, and proposes the concept of spin capacitance to quantify magnetic response to electric fields.

Contribution

It reveals a novel carrier-mediated magnetoelectric mechanism at dielectric/metal interfaces and introduces spin capacitance as a new way to quantify magnetic responses.

Findings

Demonstrates a linear magnetoelectric effect at SrRuO3/SrTiO3 interface

Defines the concept of spin capacitance for magnetic response quantification

Suggests a route to interfacial multiferroic materials

Abstract

While tremendous success has been achieved to date in creating both single phase and composite magnetoelectric materials, the quintessential electric-field control of magnetism remains elusive. In this work, we demonstrate a linear magnetoelectric effect which arises from a novel carrier-mediated mechanism, and is a universal feature of the interface between a dielectric and a spin-polarized metal. Using first-principles density functional calculations, we illustrate this effect at the SrRuO$_3$/SrTiO$_3$ interface and describe its origin. To formally quantify the magnetic response of such an interface to an applied electric field, we introduce and define the concept of spin capacitance. In addition to its magnetoelectric and spin capacitive behavior, the interface displays a spatial coexistence of magnetism and dielectric polarization suggesting a route to a new type of interfacial multiferroic.