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Bibliographic Details
Main Authors: Krebs, Zachary J., Behn, Wyatt A., Smith, Keenan J., Fortman, Margaret A., Watanabe, Kenji, Taniguchi, Takashi, Parashar, Pathak S., Fogler, Michael M., Brar, Victor W.
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2409.19468
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Table of Contents:
  • Scanning tunneling potentiometry (STP) is used to probe the local, current-induced electrochemical potential of carriers in graphene near circular electrostatic barriers in an out-of-plane magnetic field ranging from 0 to 1.4 T. These measurements provide nanometer-resolved information about the local motion of carriers, revealing significant changes in carrier dynamics with increasing field strength. At low magnetic fields the electrochemical potential displays a spiral-like pattern, while at high fields it exhibits distinct changes at particular radii. We show that the observed behavior indicates a transition from diffusive to ballistic transport. Additionally, the sharp changes in the measured potential profile at high fields result from the `spirograph' motion of carriers, which creates a local enhancement of the Hall field one cyclotron diameter away from the semiclassical turning point near the electrostatic barrier.