Direct observation of Γ moiré bands in twisted bilayer WSe2

Authors: Gianmarco Gatti (University of Geneva) , Louk Rademaker (University of Geneva) , Anna Tamai (University of Geneva) , Tobias De Jong (Leiden University) , Felix Baumberger (University of St Andrews)
Co-authored by industrial partner: No

Type: Conference Paper
Conference: APS March Meeting 2023
Peer Reviewed: No

State: Published (Approved)
Published: March 2023
Diamond Proposal Number(s): 29021

Abstract: Recent transport experiments revealed a correlated insulating phase and quantum criticality points in twisted transition metal dichalcogenides (TMDs) that were predicted to host flat moire´ mini-bands. Despite these exciting experimental observations and theoretical predictions, no direct measurements of the band structure of twisted TMD are available to date. We report here for the first time on the direct observation of flat band in twisted TMDs investigating 57° twisted bilayer WSe2 by micro-focused angle-resolved photoemission spectroscopy. We resolve multiple moire´ mini-bands with strongly reduced dispersion and significant mini-gaps. By comparison with effective continuum band structure models, we attribute the origin of the flat states to a moderate moire´ potential of ≈ 50 meV emerging from the stacking of the two semiconducting layers. Our results establish a reference for future theoretical and experimental studies of the moire´ physics in twisted TMDs.

Subject Areas: Materials, Physics

Instruments: I05-ARPES

Added On: 07/04/2023 09:55

Discipline Tags:

Quantum Materials Physics Materials Science

Technical Tags:

Spectroscopy Angle Resolved Photoemission Spectroscopy (ARPES)