Electrical Control of Structural and Physical Properties via Strong Spin-Orbit Interactions in Sr2IrO4

TL;DR

This study demonstrates how strong spin-orbit interactions in Sr2IrO4 enable electrical control over its magnetic and structural properties, leading to novel resistive switching and potential device applications.

Contribution

It reveals a new mechanism where strong spin-orbit coupling couples electrical currents to magnetic and lattice properties in Sr2IrO4, enabling control of its phase and transport characteristics.

Findings

Electrical current reduces the Néel temperature and induces lattice expansion.

Strong SOI couples magnetic moments to lattice rotations, affecting material properties.

Resistive switching is driven by non-linear lattice and magnetic responses.

Abstract

Electrical control of structural and physical properties is a long-sought, but elusive goal of contemporary science and technology. We demonstrate that a combination of strong spin-orbit interactions (SOI) and a canted antiferromagnetic (AFM) Mott state is sufficient to attain that goal. The AFM insulator Sr2IrO4 provides a model system in which strong SOI lock canted Ir magnetic moments to IrO6-octahedra, causing them to rigidly rotate together. A novel coupling between an applied electrical current and the canting angle reduces the N\'eel temperature and drives a large, non-linear lattice expansion that closely tracks the magnetization, increases the electron mobility, and precipitates a unique resistive switching effect. Our observations open new avenues for understanding fundamental physics driven by strong SOI in condensed matter, and provide a new paradigm for functional materials and devices.