Polarization-anisotropic photocurrent detection of antiferromagnetic order in FePS3

Abstract

Establishing an electrical readout of antiferromagnetic (AFM) spin order in low-dimensional materials remains a fundamental challenge. Here, we demonstrate a direct optoelectronic probe of AFM order in layered FePS3 using polarization-resolved reflectance and photocurrent measurements. Below the Néel temperature (TN), FePS3 exhibits pronounced in-plane optical anisotropy and a strongly polarization-dependent photocurrent response, whereas the photocurrent becomes nearly isotropic in the paramagnetic phase. Notably, the polarization-dependent photocurrent is closely correlated with the zigzag AFM spin configuration, highlighting the role of spin–charge light-field coupling in FePS3. Furthermore, the devices exhibit ultrahigh signal-to-noise ratios exceeding 103 at low temperatures and ultrafast photoresponse (∼2.6 μs) at room temperature. These findings establish polarization-resolved photocurrent as a practical electrical probe of AFM order and highlight its potential for exploring spin-texture-related phenomena in two-dimensional antiferromagnets.