2023, Pressure-Induced Dynamic Tuning of Interlayer Coupling in Twisted WSe2/WSe2 Homobilayers, Nano Letters

2023, Pressure-Induced Dynamic Tuning of Interlayer Coupling in Twisted WSe₂/WSe₂ Homobilayers, Nano Letters

Abstract:

Moiré superlattices induced by twisted van der Waals (vdW) heterostructures or homostructures have recently gained significant attention due to their potential to generate exotic strong-correlation electronic and phonon phenomena. However, the lack of dynamic tuning for interlayer coupling of moiré superlattices hinders a thorough understanding and development of moiré correlation state. Here, we present a dynamic tuning method for twisted WSe₂/WSe₂ homobilayers using a diamond anvil cell (DAC). We demonstrate the powerful tuning of interlayer coupling and observe an enhanced response to pressure for interlayer breathing modes and rapid descent of indirect excitons in twisted WSe2/WSe2 homobilayers. Our findings indicate that the introduction of a moiré superlattice for WSe₂ bilayers gives rise to hybridized exciton, which lead to the different pressure-evolution exciton behaviors compared to natural WSe₂ bilayers. Our results provide a novel understanding of moiré physics and offer an effective method to tune interlayer coupling of moiré superlattices. 

Keywords: Twisted homobilayer; Transition metal dichalcogenides; Hydrostatic pressure; Raman; Exciton

Link: https://pubs.acs.org/doi/10.1021/acs.nanolett.3c01640

Pressure-Induced Dynamic Tuning of Interlayer Coupling in Twisted WSe2:WSe2 Homobilayers.pdf