Electrical Tuning of Hysteresis Behavior in Two-Dimensional Ferroelectric α-In ₂ Se ₃

The ability to tune the hysteresis behavior of ferroelectric and ferromagnetic materials is crucial for optimizing their performance and broadening their functional applications. Here, we develop electric-gate-controlled strategies to tune the polarization hysteresis in α-In2Se3 by leveraging its unique in-plane and out-of-plane polarization coupling. Using first-principles calculations and Monte Carlo simulations, we demonstrate that constant and alternating gate voltages enable a wide range of tuning capabilities for the hysteresis loop in the monolayer and different stacking configurations of bilayer α-In2Se3. For monolayer α-In2Se3, constant gate voltages enable precise control over the position of the hysteresis loop, whereas alternating gate voltages reshape its profile. For bilayer α-In2Se3, different stacking configurations (3R and 2H) exhibit distinct responses: in 3R stacking, the hysteresis can be shifted or reshaped similarly to the monolayer; in 2H stacking, the gate voltage induces transitions between ferroelectric and antiferroelectric states. These findings demonstrate the potential of electric field-controlled tuning in 2D ferroic systems for functional device design.