Open AccessIn Operando Angle‐Resolved Photoemission Spectroscopy with Nanoscale Spatial Resolution: Spatial Mapping of the Electronic Structure of Twisted Bilayer Graphene
Author(s) -
Majchrzak Paulina,
Muzzio Ryan,
Jones Alfred J. H.,
Curcio Davide,
Volckaert Klara,
Biswas Deepnarayan,
Gobbo Jacob,
Singh Simranjeet,
Robinson Jeremy T.,
Watanabe Kenji,
Taniguchi Takashi,
Kim Timur K.,
Cacho Cephise,
Miwa Jill A.,
Hofmann Philip,
Katoch Jyoti,
Ulstrup Søren
Publication year - 2021
Publication title -
small science
Language(s) - English
Resource type - Journals
ISSN - 2688-4046
DOI - 10.1002/smsc.202000075
Subject(s) - graphene , materials science , mesoscopic physics , bilayer graphene , photoemission spectroscopy , condensed matter physics , electronic structure , angle resolved photoemission spectroscopy , quasiparticle , nanotechnology , x ray photoelectron spectroscopy , physics , superconductivity , nuclear magnetic resonance
To pinpoint the electronic and structural mechanisms that affect intrinsic and extrinsic performance limits of 2D material devices, it is of critical importance to resolve the electronic properties on the mesoscopic length scale of such devices under operating conditions. Herein, angle‐resolved photoemission spectroscopy with nanoscale spatial resolution (nanoARPES) is used to map the quasiparticle electronic structure of a twisted bilayer graphene device. The dispersion and linewidth of the Dirac cones associated with top and bottom graphene layers are determined as a function of spatial position on the device under both static and operating conditions. The analysis reveals that microscopic rotational domains in the two graphene layers establish a range of twist angles from 9.8° to 12.7°. Application of current and electrostatic gating lead to strong electric fields with peak strengths of 0.75 V/μm at the rotational domain boundaries in the device. These proof‐of‐principle results demonstrate the potential of nanoARPES to link mesoscale structural variations with electronic states in operating device conditions and to disentangle such extrinsic factors from the intrinsic quasiparticle dispersion.