Proximity coupling induced significantly enhanced Curie temperature in van der Waals CrSBr/MoTe2 heterostructure

CrSBr monolayer is a promising ferromagnetic (FM) semiconductor with stable magnetic ground state, large bandgap, and high carrier density. However, its Curie temperature (T-C) of about 146 K is still below room temperature. Herein, electronic and magnetic properties of a CrSBr/MoTe2 heterostructure are explored to boost the T-C via the proximity effect using first-principles calculations. The long-range FM ordering in the CrSBr layer is enhanced both through an extra spin superexchange channel (Cr-Te-Cr) afforded by the MoTe2 substrate and the reduced degeneracy t(2)(g) orbitals of Cr atoms. Directly owing to the enhanced FM coupling, T-C increases to 225 K. The strong p-d hybridizations increase the interorbital hopping between the t(2)(g) states through the Cr-Te-Cr superexchange channel. The hopping is related to the off diagonal matrix element of the velocity operator, which suggests that is necessary for not only the increased T-C but also the nonzero Berry curvature. Additionally, the Fermi level (E-F) is pushed into higher energy levels with the electron-doped CrSBr layer due to the charge transfer. The synergic effect of the E-F shift from the transferred electron filling and the interorbital hopping from the Cr-Te interaction results in nonzero anomalous Hall conductivity in the heterostructure. Our work reveals that an interface is an uplifting way for engineering the magnetic and transport properties of 2D magnets, providing opportunities for fantastic spintronic devices. Published under an exclusive license by AIP Publishing.

Automated summary

In this research, the electronic and magnetic properties of a CrSBr/MoTe2 heterostructure are explored using first-principles calculations. The results show that the Curie temperature of the CrSBr layer can be increased by the proximity effect, resulting in enhanced ferromagnetic ordering. The interorbital hopping and charge transfer in the heterostructure contribute to the nonzero anomalous Hall conductivity.