In Operando Angle-Resolved Photoemission Spectroscopy with Nanoscale Spatial Resolution: Spatial Mapping of the Electronic Structure of Twisted Bilayer Graphene

TY - JOUR

T1 - In Operando Angle-Resolved Photoemission Spectroscopy with Nanoscale Spatial Resolution: Spatial Mapping of the Electronic Structure of Twisted Bilayer Graphene

AU - Majchrzak, Paulina

AU - Muzzio, Ryan

AU - Jones, Alfred J. H.

AU - Curcio, Davide

AU - Volckaert, Klara

AU - Biswas, Deepnarayan

AU - Gobbo, Jacob

AU - Singh, Simranjeet

AU - Robinson, Jeremy T.

AU - Watanabe, Kenji

AU - Taniguchi, Takashi

AU - Kim, Timur K.

AU - Cacho, Cephise

AU - Miwa, Jill A.

AU - Hofmann, Philip

AU - Katoch, Jyoti

AU - Ulstrup, Søren

PY - 2021/6

Y1 - 2021/6

N2 - 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.

AB - 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.

KW - 2D material devices

KW - angle-resolved photoemission spectroscopy with nanoscale spatial resolution

KW - electron transport

KW - twisted bilayer graphene

KW - van der Waals heterostructures

UR - https://www.scopus.com/pages/publications/85165281154

U2 - 10.1002/smsc.202000075

DO - 10.1002/smsc.202000075

M3 - Journal article

SN - 2688-4046

VL - 1

SP - 2000075

JO - Small Science

JF - Small Science

IS - 6

M1 - 2000075

ER -