Interfacial Magnetic Coupling and Valley Exciton Control in Double Proximity MoS2 Heterostructures

Abstract

The magnetic proximity effect (MPE) in two-dimensional transition metal dichalcogenides (TMDCs) offers a compelling route to manipulate spin and valley degrees of freedom for next-generation quantum technologies. While TMDCs interfaced with magnetic materials provide a versatile platform for tailoring interfacial magnetic interactions, precise control of MPE remains elusive, particularly in the presence of dual magnetic interfaces. Here, we report the emergence of complex magneto-optical phenomena in a CrOCl–MoS₂–YIG heterostructure, where MoS₂ is simultaneously interfaced with an antiferromagnet (CrOCl) and a ferromagnet (YIG). The CrOCl layer induces strong p-type doping in MoS₂, resulting in a 14-fold enhancement of photoluminescence quantum efficiency at cryogenic temperatures. Valley-polarized photoluminescence spectra under magnetic field show that pronounced sensitivity of MoS₂ excitons to the magnetic ordering of CrOCl, which reveals the competitive interactions at the CrOCl–MoS₂ and MoS₂–YIG interfaces. Furthermore, interfacial symmetry breaking at the CrOCl–MoS₂ boundary induces pronounced exciton linear polarization, with the polarization axis rotating up to 90° under magnetic tuning, highlighting the synergistic effect of valley coherence and Faraday effect. Our findings reveal the complex interfacial physics arising from dual magnetic proximity and provide a versatile strategy for realizing magnetically reconfigurable valley polarization in two-dimensional semiconductors.