Highly Tunable Moiré Superlattice Potentials in Twisted Hexagonal Boron Nitrides

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Twisted hexagonal boron nitride (hBN) van der Waals heterostructures exhibit interfacial ferroelectricity.
• Nanoscale moiré potentials in twisted hBN can induce remote Coulomb superlattices in adjacent 2D materials.
• Engineering moiré superlattices is crucial for developing programmable quantum materials.

Purpose of the Study:

• To demonstrate the realization and characterization of twisted hBN-based moiré superlattice platforms.
• To investigate methods for controlling moiré length, angle, and potential strength.
• To explore in-situ manipulation of moiré potentials for novel quantum applications.

Main Methods:

• Fabrication of twisted hBN moiré superlattices using precise piezo stage stacking and heat annealing.
• Visualization of moiré domains and ferroelectric properties via Kelvin probe force microscopy (KPFM).
• In-situ manipulation of moiré potential using femtosecond pulse laser irradiation.

Main Results:

• Achieved large-area, regular moiré superlattices with uniform structures.
• Demonstrated cumulative multi-ferroelectric polarization and multi-level domains.
• Observed quasi-1D anisotropic moiré domains and high-resolution strain analysis.
• Showcased optical phonon-induced atomic displacement via laser manipulation.

Conclusions:

• Precisely programmable moiré superlattice platforms can be developed using twisted hBN.
• These platforms offer new avenues for investigating strongly correlated quantum physics.
• The demonstrated techniques enable fine-tuning of moiré superlattice properties for advanced material design.