Switchable half-metallicity in anti-ferromagnetic bilayer NbS₂

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Electrical control of spin in spintronics offers advantages over magnetic control, including efficiency and reduced energy consumption.
• Direct electrical control faces volatility challenges, making indirect methods using ferroelectric materials more attractive.
• Antiferromagnetic materials offer unique spintronic properties but require effective control mechanisms.

Purpose of the Study:

• To propose and investigate a novel indirect electrical control strategy for achieving half-metallicity in antiferromagnetic bilayer NbS2.
• To explore the potential of sliding ferroelectricity as an effective mechanism for spin control.
• To provide an alternative route for realizing switchable half-metallicity in 2D antiferromagnetic systems.

Main Methods:

• Density functional theory (DFT) calculations were employed to investigate the electronic and magnetic properties of antiferromagnetic bilayer NbS2.
• The study focused on analyzing the effects of sliding ferroelectricity and the induced built-in electric field on the material's band structure.
• Spin splitting and band gap modifications were examined to determine the emergence of half-metallicity.

Main Results:

• Switchable sliding interlayer ferroelectricity was successfully predicted in antiferromagnetic bilayer NbS2.
• The induced out-of-plane polarization creates a potential energy difference, leading to significant spin splitting in the band structure.
• Despite weak sliding ferroelectricity, the strong spin splitting closes the band gap in one spin channel, resulting in half-metallicity.

Conclusions:

• Sliding ferroelectricity provides an effective indirect electrical control method for inducing half-metallicity in antiferromagnetic bilayer NbS2.
• This approach offers a viable alternative to intrinsic ferroelectric control for spintronic applications.
• The findings extend the practical applications of 2D antiferromagnetic materials by enabling switchable half-metallicity.