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Title: Imaging ballistic carrier trajectories in graphene using scanning gate microscopy

We use scanning gate microscopy to map out the trajectories of ballistic carriers in high-mobility graphene encapsulated by hexagonal boron nitride and subject to a weak magnetic field. We employ a magnetic focusing geometry to image carriers that emerge ballistically from an injector, follow a cyclotron path due to the Lorentz force from an applied magnetic field, and land on an adjacent collector probe. The local electric field generated by the scanning tip in the vicinity of the carriers deflects their trajectories, modifying the proportion of carriers focused into the collector. By measuring the voltage at the collector while scanning the tip, we are able to obtain images with arcs that are consistent with the expected cyclotron motion. We also demonstrate that the tip can be used to redirect misaligned carriers back to the collector.
Authors:
;  [1] ; ; ; ;  [2] ; ;  [3] ;  [1] ;  [4]
  1. Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan)
  2. Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE (United Kingdom)
  3. National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)
  4. (Japan)
Publication Date:
OSTI Identifier:
22486244
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 24; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BORON NITRIDES; CARRIERS; CYCLOTRONS; ELECTRIC FIELDS; ELECTRIC POTENTIAL; FOCUSING; GEOMETRY; GRAPHENE; IMAGES; LORENTZ FORCE; MAGNETIC FIELDS; MAPS; MICROSCOPY; MOBILITY; PROBES; TRAJECTORIES