Back to Search
Start Over
ARPES Signatures of Few-Layer Twistronic Graphenes.
- Source :
-
Nano letters [Nano Lett] 2023 Jun 14; Vol. 23 (11), pp. 5201-5208. Date of Electronic Publication: 2023 May 26. - Publication Year :
- 2023
-
Abstract
- Diverse emergent correlated electron phenomena have been observed in twisted-graphene layers. Many electronic structure predictions have been reported exploring this new field, but with few momentum-resolved electronic structure measurements to test them. We use angle-resolved photoemission spectroscopy to study the twist-dependent (1° < θ < 8°) band structure of twisted-bilayer, monolayer-on-bilayer, and double-bilayer graphene (tDBG). Direct comparison is made between experiment and theory, using a hybrid k · p model for interlayer coupling. Quantitative agreement is found across twist angles, stacking geometries, and back-gate voltages, validating the models and revealing field-induced gaps in twisted graphenes. However, for tDBG at θ = 1.5 ± 0.2°, close to the magic angle θ = 1.3°, a flat band is found near the Fermi level with measured bandwidth E <subscript>w</subscript> = 31 ± 5 meV. An analysis of the gap between the flat band and the next valence band shows deviations between experiment (Δ <subscript>h</subscript> = 46 ± 5 meV) and theory (Δ <subscript>h</subscript> = 5 meV), indicative of lattice relaxation in this regime.
Details
- Language :
- English
- ISSN :
- 1530-6992
- Volume :
- 23
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- Nano letters
- Publication Type :
- Academic Journal
- Accession number :
- 37235208
- Full Text :
- https://doi.org/10.1021/acs.nanolett.3c01173