Pressure-Induced Dynamic Tuning of Interlayer Coupling in Twisted WSe₂/WSe₂ Homobilayers

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Moiré superlattices in twisted van der Waals (vdW) materials offer potential for novel electronic and phonon phenomena.
• Current limitations in dynamically tuning interlayer coupling hinder the full exploration of moiré correlation states.

Purpose of the Study:

• To develop a method for dynamic tuning of interlayer coupling in moiré superlattices.
• To investigate the impact of tunable interlayer coupling on electronic and phonon properties in twisted WSe2/WSe2 homobilayers.

Main Methods:

• Utilized a diamond anvil cell (DAC) to apply pressure and dynamically tune interlayer coupling in twisted WSe2/WSe2 homobilayers.
• Investigated pressure-dependent responses of interlayer breathing modes and exciton behaviors.

Main Results:

• Demonstrated effective dynamic tuning of interlayer coupling via pressure.
• Observed enhanced pressure response for interlayer breathing modes.
• Reported a rapid descent of indirect excitons in twisted WSe2/WSe2 homobilayers.
• Identified hybridized excitons in moiré superlattices leading to distinct pressure-evolution exciton behaviors compared to natural WSe2 bilayers.

Conclusions:

• The developed DAC method provides a novel approach to tune interlayer coupling in moiré superlattices.
• The findings offer new insights into moiré physics, particularly the role of hybridized excitons and their pressure dependence.
• This work facilitates further research and development of moiré-based electronic and phonon devices.