3 research outputs found
Direct evidence for flat bands in twisted bilayer graphene from nano-ARPES
Transport experiments in twisted bilayer graphene revealed multiple
superconducting domes separated by correlated insulating states. These
properties are generally associated with strongly correlated states in a flat
mini-band of the hexagonal moir\'e superlattice as it was predicted by band
structure calculations. Evidence for such a flat band comes from local
tunneling spectroscopy and electronic compressibility measurements, reporting
two or more sharp peaks in the density of states that may be associated with
closely spaced van Hove singularities. Direct momentum resolved measurements
proved difficult though. Here, we combine different imaging techniques and
angle resolved photoemission with simultaneous real and momentum space
resolution (nano-ARPES) to directly map the band dispersion in twisted bilayer
graphene devices near charge neutrality. Our experiments reveal large areas
with homogeneous twist angle that support a flat band with spectral weight that
is highly localized in momentum space. The flat band is separated from the
dispersive Dirac bands which show multiple moir\'e hybridization gaps. These
data establish the salient features of the twisted bilayer graphene band
structure.Comment: Submitted to Nature Materials. Nat. Phys. (2020
Observation of flat bands in twisted bilayer graphene (source data)
AbstractSource data of manuscript "Observation of flat bands in twisted bilayer graphene" by Simone Lisi et al. published in Nature Physics