skip to main content

SciTech ConnectSciTech Connect

Title: Local imaging of high mobility two-dimensional electron systems with virtual scanning tunneling microscopy

Correlated electron states in high mobility two-dimensional electron systems (2DESs), including charge density waves and microemulsion phases intermediate between a Fermi liquid and Wigner crystal, are predicted to exhibit complex local charge order. Existing experimental studies, however, have mainly probed these systems at micron to millimeter scales rather than directly mapping spatial organization. Scanning probes should be well-suited to study the spatial structure of these states, but high mobility 2DESs are found at buried semiconductor interfaces, beyond the reach of conventional scanning tunneling microscopy. Scanning techniques based on electrostatic coupling to the 2DES deliver important insights, but generally with resolution limited by the depth of the 2DES. In this letter, we present our progress in developing a technique called “virtual scanning tunneling microscopy” that allows local tunneling into a high mobility 2DES. Using a specially designed bilayer GaAs/AlGaAs heterostructure where the tunnel coupling between two separate 2DESs is tunable via electrostatic gating, combined with a scanning gate, we show that the local tunneling can be controlled with sub-250 nm resolution.
Authors:
 [1] ;  [2] ;  [2] ; ;  [3] ;  [2] ;  [1] ;  [2] ; ;  [4]
  1. Department of Applied Physics, Stanford University, 348 Via Pueblo Mall, Stanford, California 94305 (United States)
  2. (United States)
  3. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)
  4. Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 (United States)
Publication Date:
OSTI Identifier:
22391900
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 18; Other Information: (c) 2014 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; ALUMINIUM ARSENIDES; CHARGE DENSITY; CRYSTALS; ELECTRON CORRELATION; ELECTRON MOBILITY; ELECTRONS; FERMI GAS; GALLIUM ARSENIDES; LAYERS; MICROEMULSIONS; SCANNING TUNNELING MICROSCOPY; SEMICONDUCTOR MATERIALS; TUNNEL EFFECT; TWO-DIMENSIONAL SYSTEMS