Strain‐Valley Coupling in 2D Antiferromagnetic Lattice

Abstract In recent years, 2D valley physics has attracted tremendous attention in both fundamental research and device applications. The search for a coupling valley with exotic physical properties can enable the exploration of novel quantum devices and is therefore of significant interest. Here, using model analysis, a novel mechanism is proposed that realizes strong coupling between strain and valley physics in a 2D antiferromagnetic honeycomb lattice in a controllable fashion. This idea is to modulate the exchange interactions through strain, thereby mediating the inversion and time‐reversal symmetries. As valley physics are connected with the symmetries, this enables a strong strain‐valley coupling. On the basis of first‐principles calculations, the validity of this mechanism is further demonstrated in a series of single‐layer systems, i.e., AuCl₃, CrI₃, and VPTe₃, which are predicted to host valley polarization and anomalous valley Hall effect. The change in bonding angle is found to play a crucial role in mediating the exchange interaction and thus the strain‐valley coupling process. The microscopic origin is also discussed. These explored phenomena and insights greatly enrich the valley physics and 2D materials research.