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

Small Science

Ryan Muzzio¹  Jacob Gobbo¹  Jyoti Katoch¹  Simranjeet Singh¹  Philip Hofmann²  Deepnarayan Biswas²  Davide Curcio²  Alfred J. H. Jones²  Søren Ulstrup²  Jill A. Miwa²  Paulina Majchrzak²  Klara Volckaert²  Cephise Cacho³  Timur K. Kim³  Jeremy T. Robinson⁴  Takashi Taniguchi⁵  Kenji Watanabe⁶ 

[1] Department of Physics Carnegie Mellon University Pittsburgh, Pennsylvania 15213 USA;Department of Physics and Astronomy Aarhus University 8000 Aarhus C Denmark;Diamond Light Source Division of Science Didcot United Kingdom;Electronics Science and Technology Division US Naval Research Laboratory Washington D.C 20375 USA;International Center for Materials Nanoarchitectonics National Institute for Materials Science 1-1 Namiki Tsukuba 305-0044 Japan;Research Center for Functional Materials National Institute for Materials Science 1-1 Namiki Tsukuba 305-0044 Japan;

关键词: 2D material devices;    angle-resolved photoemission spectroscopy with nanoscale spatial resolution;    electron transport;    twisted bilayer graphene;    van der Waals heterostructures;   

DOI  :  10.1002/smsc.202000075

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown