Coexisting Magnetism, Ferroelectric, and Ferrovalley Multiferroic in Stacking-Dependent Two-Dimensional Materials

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Two-dimensional (2D) multiferroic materials are crucial for advanced nanodevices.
• Coupling magnetic, ferroelectric, and ferrovalley properties in a single 2D material remains a challenge.

Purpose of the Study:

• To propose and investigate a mechanism for manipulating coupled multiferroic properties in 2D materials.
• To explore the potential of interlayer sliding for tunable and reversible control of magnetism, ferroelectricity, and valley polarization.

Main Methods:

• Theoretical proposal of interlayer sliding in a 2D bilayer material.
• Investigation of monolayer and bilayer GdI2 properties using theoretical calculations.
• Analysis of magnetic phase transitions via spin Hamiltonian and inter-layer electron hopping.

Main Results:

• Monolayer GdI2 exhibits ferromagnetic semiconducting behavior with significant valley polarization (up to 155.5 meV).
• Bilayer GdI2 demonstrates strong coupling between magnetism and valley polarization, tunable and reversible via ferroelectric sliding.
• Microscopic mechanisms for magnetic phase transitions were elucidated.

Conclusions:

• Interlayer sliding offers a novel pathway to achieve coupled multiferroic properties in 2D materials.
• The findings provide a new direction for developing next-generation electronic, valleytronic, and spintronic devices.