Switchable moiré potentials in ferroelectric WTe₂/WSe₂ superlattices

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Moiré materials exhibit strong electronic correlations and tunable band topology.
• Controlling moiré potentials non-volatilely for switching superlattice effects remains a challenge.

Purpose of the Study:

• To demonstrate non-volatile switching of correlated and moiré band insulating states using ferroelectric control.
• To investigate the associated nonlinear anomalous Hall effect in ferroelectric moiré materials.

Main Methods:

• Fabrication of a ferroelectric WTe2 bilayer (Td structure) interfaced with a WSe2 monolayer (H structure) to create a moiré superlattice.
• Utilizing the ferroelectric effect to control moiré potential depth via polarization-dependent charge transfer.

Main Results:

• Successfully switched correlated and moiré band insulating states using ferroelectric switching.
• Observed the nonlinear anomalous Hall effect, which is tunable with ferroelectric polarization.
• Demonstrated that ferroelectric switching effectively turns moiré insulating states on and off.

Conclusions:

• Ferroelectric control offers a viable pathway for non-volatile switching of moiré superlattice effects.
• This work opens avenues for new functional moiré materials by integrating intrinsic symmetry-breaking orders.
• The findings highlight the potential of ferroelectric WTe2 bilayers for tunable electronic and topological properties.