Optical Readout of Reconfigurable Layered Magnetic Domain Structure in CrSBr

TL;DR

This paper demonstrates a non-destructive optical method to read and control layered magnetic states in CrSBr, a van der Waals magnetic semiconductor, enabling advanced spin-optoelectronic applications.

Contribution

It introduces a purely optical, multilayer model-based readout of magnetic configurations in CrSBr, including tunability via magnetic fields and interfaces, revealing complex intermediate magnetic states.

Findings

Optical magneto-reflectance effectively distinguishes magnetic states.

Magnetic transitions involve multiple intermediate configurations.

Layer thickness and interfaces influence magnetic stability and multiplicity.

Abstract

The van der Waals magnetic semiconductor CrSBr combines multistable magnetic order with strong light--matter coupling, enabling optical access to a rich and reconfigurable layered magnetic domain structure. A purely optical, non-destructive, and non-contact readout of layered magnetic configurations is realized here by magneto-reflectance measurements and interpreted using an optical multilayer model. The magnetic state is tunable by applied magnetic fields and by interfacing CrSBr with the antiferromagnet MnPS$_3$. Applying an external magnetic field along the easy axis drives the hysteretic antiferromagnetic--to--ferromagnetic transition, which is not universally binary but instead develops through a cascade of intermediate magnetic configurations whose multiplicity and stability scale systematically with layer thickness and can be tailored by magnetic interfaces. The intertwined optical and magnetic properties of CrSBr provide a readout mechanism for information encoded in and processed through its magnetic configuration that is compatible with modern on- and off-chip photonic and electronic technologies. These properties identify CrSBr as a promising platform for intelligent matter and for spin-optoelectronics, in particular for neuromorphic architectures that can learn and evolve in response to changing environments.