Two-dimensional (2D) antiferromagnetic (AFM) heterostructures (HTSs) have broad application prospects since they offer a stray-free field, robustness against magnetic perturbations, and faster spin dynamics, but how to effectively control valley polarization with an AFM substrate is still an issue. Here spin−valley physical coupling in monolayers of MoSi 2 N 4 and AFM MnPS 3 is due to spin−orbit coupling and the absence of inversion symmetry, which made broad application prospects of spin and valley in novel 2D materials. Spontaneous valley polarization in MoSi 2 N 4 /MnPS 3 HTS has been confirmed by using the first-principles calculations and low-energy effective Hamiltonian models. We reveal that its Neél temperature calculated by Monte Carlo simulation is about 340 K above room temperature, which is higher than many 2D AFM materials. The magnetic proximity phenomenon caused by interfacial orbital hybridization is gradually strengthened thanks to the reduction of the distance between the two layers, and valley splitting of the MoSi 2 N 4 /MnPS 3 HTS is calculated to be Δ K−K′ = 9.15 meV. Our computational results offer a basis for the valley polarization in an intrinsic AFM HTS and a practical approach to design and utilize valleytronics devices.

Combining the nontrivial band topology with the intrinsic ferrovalley (FV), the valley-nonequilibrium quantum anomalous Hall effect (VQAHE) attracts growing attention both for its potential applications and basic physics. The electronic properties of some systems with localized orbital distribution and special structures could be influenced by the electronic correlation effect. In our work, the electronic correlation effect on the electronic structures for a Janus RuClF monolayer (ML) is investigated based on the first-principles calculations + U method. For the magnetization orientation along the out-of-plane (OOP) direction, RuClF ML undergoes FV to half-valley-metal (HVM) to VQAHE to HVM to FV transitions with increasing electron correlation effects. There is a chiral edge state connecting the valence and conduction bands and an integer Chern number (C = 1) when 2.52 < U < 2.55 eV. No obvious valley polarization and special VQAHE phases occur for the magnetization orientation along the in-plane (IP) direction. Regardless of IP or OOP magnetic anisotropy, the sign-reversible Berry curvature can be found with increasing U values. Notably, with increasing U values, the magnetization of RuClF ML varies from OOP to IP, and the key U value is approximately 2.41 eV. When taking into account the intrinsic magnetic anisotropy, no HVM and VQAHE states exist. This work finds the significance of magnetic anisotropy and electronic correlation effects in RuClF ML and highlights that electronic correlation effects can induce unusual topological phase transitions. Our consequences manifest that RuClF ML is an admirable material for topological electronic, spintronic, and valleytronic applications.