Comprehensive Control of Metamagnetic Transition of Antiferromagnetic Mott Insulator Sr2IrO4 by in-situ Anisotropic Strain

TL;DR

This study demonstrates that a tiny anisotropic strain can significantly control the metamagnetic transition in Sr2IrO4, enabling electrical switching and revealing the role of magnetic anisotropy in spin-orbit-coupled Mott insulators.

Contribution

It introduces a method to in-situ tune the metamagnetic transition in Sr2IrO4 using minimal anisotropic strain, linking magnetic anisotropy to transition type and electronic responses.

Findings

0.05% strain modulates critical field by over 50%

Transition switches from spin-flop to spin-flip with strain

Large elasto- and magnetoconductance observed

Abstract

Metamagnetism in antiferromagnets exhibits distinct critical behaviors and dynamics when invoking spin reversal and rotation. Here we show a 0.05% anisotropic strain suffices to in-situ modulate the metamagnetic critical field of the Mott insulator Sr2IrO4 by over 50%, enabling electrical switching of the transition. Resonant x-ray scattering and model simulation reveal that the transition is completely tuned from the spin-flop to spin-flip type as the strain introduces C4-symmetry-breaking magnetic anisotropy. Simultaneous transport study indicates the metamagnetic responses are reflected in the large elasto- and magnetoconductance, highlighting the active charge degree of freedom in the spin-orbit-coupled Mott state and its potential for spin-electronics.