Multiferroic materials for spin-based logic devices

TL;DR

This paper explores how multiferroic materials, which combine ferroelectric and magnetic properties, can enable low-power, electric-field-controlled spin-wave devices for advanced spin-based logic applications.

Contribution

It demonstrates the potential of multiferroic magnetoelectrics for electric-field manipulation of spin waves, introducing a phenomenological Landau theory to explain these effects.

Findings

Spin-wave properties can be controlled by electric fields in multiferroics.

The coupling between polarization and magnetic order depends on material state.

BiFeO3 exhibits subtle differences in behavior between crystalline and film forms.

Abstract

Logical devices based on spin waves offer the potential to avoid dissipation mechanisms that limit devices based on either the charge or spin of mobile electrons. Multiferroic magnetoelectrics, which are materials that combine ferroelectric and magnetic order, allow direct switching of magnetic order and thence of spin-wave properties using an applied electric field. The intrinsic coupling between polarization and magnetic moments, generated by strong electronic correlations in these multiferroic materials, is argued to provide new approaches to spin-wave injection and spin-wave switching using applied voltages with no external magnetic field. These effects are shown to arise in a phenomenological Landau theory of coupled electronic and magnetic orders in multiferroic BiFeO3, and found to depend subtly on differences between the crystalline and film states of this material.