Giant anisotropic magnetoresistance and nonvolatile memory in canted antiferromagnet Sr2IrO4

TL;DR

This paper reports giant anisotropic magnetoresistance and nonvolatile memory effects in Sr2IrO4 antiferromagnet, demonstrating potential for advanced AFM spintronic devices with enhanced readout capabilities and bistable states.

Contribution

It reveals a giant AMR of ~160% in Sr2IrO4 without auxiliary layers and demonstrates nonvolatile memory switching with Ga-doping, advancing AFM spintronics.

Findings

Giant AMR (~160%) achieved in Sr2IrO4 without reference layer.

Nonvolatile memory states switchable in-situ, stable at zero field.

Ga-doping modifies interlayer coupling, enabling bistability.

Abstract

Antiferromagnets have been generating intense interest in the spintronics community, owing to their intrinsic appealing properties like zero stray field and ultrafast spin dynamics. While the control of antiferromagnetic (AFM) orders has been realized by various means, applicably appreciated functionalities on the readout side of AFM-based devices are urgently desired. Here, we report the remarkably enhanced anisotropic magnetoresistance (AMR) as giant as ~ 160% in a simple resistor structure made of AFM Sr2IrO4 without auxiliary reference layer. The underlying mechanism for the giant AMR is an indispensable combination of atomic scale giant-MR-like effect and magnetocrystalline anisotropy energy, which was not accessed earlier. Furthermore, we demonstrate the bistable nonvolatile memory states that can be switched in-situ without the inconvenient heat-assisted procedure, and robustly preserved even at zero magnetic field, due to the modified interlayer coupling by 1% Ga-doping in Sr2IrO4. These findings represent a straightforward step toward the AFM spintronic devices.