Strain and U driven phase transitions in monolayer intrinsic ferrovalley NbIn2As2Se2†

Abstract

The manipulation of the valley degree of freedom presents opportunities for both research and practical application. In this work, we theoretically demonstrate that the intrinsic valley anomalous Hall effect can exist in monolayer NbIn₂As₂Se₂. Due to time-reversal symmetry breaking, monolayer NbIn₂As₂Se₂ is an out-of-plane magnetization semiconductor with a Curie temperature of 232 K. The ability to induce phase transitions in the material through strain and the U value leads to different electronic states like the valley quantum anomalous Hall effect and the half-valley-metal state. The chiral-spin-valley locking of edge states and the band inversion of the d orbital of Nb at the K/K′ valley offer insights into the mechanisms behind these transitions. These findings not only contribute to the fundamental understanding of topology, spintronics, and valleytronics, but also pave the way for potential practical applications and experimental investigations in this exciting and rapidly evolving field.