Valley polarization in a two-dimensional high-temperature semiconducting TiInTe[formula omitted] honeycomb ferromagnet

Abstract

Exploring valley-contrasting physics in scarce intrinsic high-temperature ferromagnetic semiconductors with feasible synthesis route is of great significance for ever-evolving moden information technology. By first-principles calculations, the TiInTe3 monolayer is predicted to demonstrate excellent structural stability and easy-plane semiconducting ferromagnetism arising from indirect superexchange mechanism. Monte Carlo simulations based on the Heisenberg model reveal a magnetic phase transition at 583 K well above room temperature. Due to the inversion and time-reversal asymmetries, tunable valley polarization in the conduction band up to 110 meV can be achieved by varying the magnetization orientation, which is further validated by a first-order perturbation theory. More excitingly, electron doping for realizing the anomalous valley Hall effect gives rise to an out-of-plane preference for magnetization in the TiInTe3 monolayer and thus generates spontaneous and larger valley polarizations. After doping, the ferromagnetism above room temperature remains robust in the experimentally attainable electron density regime. Our findings highlight that the TiInTe3 monolayer is a promising ferrovalley material for developing high-performance spintronic and valleytronic nanodevices.