Imaging coherent electron flow in a two-dimensional electron gas

Brian J Leroy, M. A. Topinka, A. C. Bleszynski, R. M. Westervelt, S. E J Shaw, E. J. Heller, K. D. Maranowski, A. C. Gossard

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Scanning probe microscopy (SPM) has been used to obtain images of electron flow through a two-dimensional electron gas from a quantum point contact (QPC) inside a GaAs/AlGaAs heterostructure at liquid He temperatures. A negatively charged SPM tip depletes the electron gas immediately below and decreases the conductance of the QPC by backscattering electrons. Images of electron flow are obtained by recording the conductance, as the tip is scanned across the structure. At distances less than 1μm from the QPC, the electron flow shows angular lobes that are characteristic of the quantum modes of the QPC. At distances greater than 1 μm, well-defined branches of electron flow are observed that are caused by the cumulative effects of small angle scattering by ionized donor and impurity atoms. Interference fringes spaced by half the Fermi wavelength decorate all of the images of electron flow; their spacing gives a spatial profile of the electron density.

Original languageEnglish (US)
Pages (from-to)134-139
Number of pages6
JournalApplied Surface Science
Volume210
Issue number1-2 SPEC.
DOIs
StatePublished - Mar 31 2003
Externally publishedYes

Fingerprint

Two dimensional electron gas
electron gas
Point contacts
Imaging techniques
Electrons
Scanning probe microscopy
electrons
microscopy
Electron gas
scanning
probes
Backscattering
lobes
Carrier concentration
aluminum gallium arsenides
Heterojunctions
backscattering
recording
spacing
Scattering

Keywords

  • GaAs
  • Quantum point contact
  • Scanning probe microscopy
  • Two-dimensional electron gas

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Condensed Matter Physics

Cite this

Leroy, B. J., Topinka, M. A., Bleszynski, A. C., Westervelt, R. M., Shaw, S. E. J., Heller, E. J., ... Gossard, A. C. (2003). Imaging coherent electron flow in a two-dimensional electron gas. Applied Surface Science, 210(1-2 SPEC.), 134-139. https://doi.org/10.1016/S0169-4332(02)01493-9

Imaging coherent electron flow in a two-dimensional electron gas. / Leroy, Brian J; Topinka, M. A.; Bleszynski, A. C.; Westervelt, R. M.; Shaw, S. E J; Heller, E. J.; Maranowski, K. D.; Gossard, A. C.

In: Applied Surface Science, Vol. 210, No. 1-2 SPEC., 31.03.2003, p. 134-139.

Research output: Contribution to journalArticle

Leroy, BJ, Topinka, MA, Bleszynski, AC, Westervelt, RM, Shaw, SEJ, Heller, EJ, Maranowski, KD & Gossard, AC 2003, 'Imaging coherent electron flow in a two-dimensional electron gas', Applied Surface Science, vol. 210, no. 1-2 SPEC., pp. 134-139. https://doi.org/10.1016/S0169-4332(02)01493-9
Leroy BJ, Topinka MA, Bleszynski AC, Westervelt RM, Shaw SEJ, Heller EJ et al. Imaging coherent electron flow in a two-dimensional electron gas. Applied Surface Science. 2003 Mar 31;210(1-2 SPEC.):134-139. https://doi.org/10.1016/S0169-4332(02)01493-9
Leroy, Brian J ; Topinka, M. A. ; Bleszynski, A. C. ; Westervelt, R. M. ; Shaw, S. E J ; Heller, E. J. ; Maranowski, K. D. ; Gossard, A. C. / Imaging coherent electron flow in a two-dimensional electron gas. In: Applied Surface Science. 2003 ; Vol. 210, No. 1-2 SPEC. pp. 134-139.
@article{37f0abbe73d94091b29c5280ad74c682,
title = "Imaging coherent electron flow in a two-dimensional electron gas",
abstract = "Scanning probe microscopy (SPM) has been used to obtain images of electron flow through a two-dimensional electron gas from a quantum point contact (QPC) inside a GaAs/AlGaAs heterostructure at liquid He temperatures. A negatively charged SPM tip depletes the electron gas immediately below and decreases the conductance of the QPC by backscattering electrons. Images of electron flow are obtained by recording the conductance, as the tip is scanned across the structure. At distances less than 1μm from the QPC, the electron flow shows angular lobes that are characteristic of the quantum modes of the QPC. At distances greater than 1 μm, well-defined branches of electron flow are observed that are caused by the cumulative effects of small angle scattering by ionized donor and impurity atoms. Interference fringes spaced by half the Fermi wavelength decorate all of the images of electron flow; their spacing gives a spatial profile of the electron density.",
keywords = "GaAs, Quantum point contact, Scanning probe microscopy, Two-dimensional electron gas",
author = "Leroy, {Brian J} and Topinka, {M. A.} and Bleszynski, {A. C.} and Westervelt, {R. M.} and Shaw, {S. E J} and Heller, {E. J.} and Maranowski, {K. D.} and Gossard, {A. C.}",
year = "2003",
month = "3",
day = "31",
doi = "10.1016/S0169-4332(02)01493-9",
language = "English (US)",
volume = "210",
pages = "134--139",
journal = "Applied Surface Science",
issn = "0169-4332",
publisher = "Elsevier",
number = "1-2 SPEC.",

}

TY - JOUR

T1 - Imaging coherent electron flow in a two-dimensional electron gas

AU - Leroy, Brian J

AU - Topinka, M. A.

AU - Bleszynski, A. C.

AU - Westervelt, R. M.

AU - Shaw, S. E J

AU - Heller, E. J.

AU - Maranowski, K. D.

AU - Gossard, A. C.

PY - 2003/3/31

Y1 - 2003/3/31

N2 - Scanning probe microscopy (SPM) has been used to obtain images of electron flow through a two-dimensional electron gas from a quantum point contact (QPC) inside a GaAs/AlGaAs heterostructure at liquid He temperatures. A negatively charged SPM tip depletes the electron gas immediately below and decreases the conductance of the QPC by backscattering electrons. Images of electron flow are obtained by recording the conductance, as the tip is scanned across the structure. At distances less than 1μm from the QPC, the electron flow shows angular lobes that are characteristic of the quantum modes of the QPC. At distances greater than 1 μm, well-defined branches of electron flow are observed that are caused by the cumulative effects of small angle scattering by ionized donor and impurity atoms. Interference fringes spaced by half the Fermi wavelength decorate all of the images of electron flow; their spacing gives a spatial profile of the electron density.

AB - Scanning probe microscopy (SPM) has been used to obtain images of electron flow through a two-dimensional electron gas from a quantum point contact (QPC) inside a GaAs/AlGaAs heterostructure at liquid He temperatures. A negatively charged SPM tip depletes the electron gas immediately below and decreases the conductance of the QPC by backscattering electrons. Images of electron flow are obtained by recording the conductance, as the tip is scanned across the structure. At distances less than 1μm from the QPC, the electron flow shows angular lobes that are characteristic of the quantum modes of the QPC. At distances greater than 1 μm, well-defined branches of electron flow are observed that are caused by the cumulative effects of small angle scattering by ionized donor and impurity atoms. Interference fringes spaced by half the Fermi wavelength decorate all of the images of electron flow; their spacing gives a spatial profile of the electron density.

KW - GaAs

KW - Quantum point contact

KW - Scanning probe microscopy

KW - Two-dimensional electron gas

UR - http://www.scopus.com/inward/record.url?scp=0037474576&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037474576&partnerID=8YFLogxK

U2 - 10.1016/S0169-4332(02)01493-9

DO - 10.1016/S0169-4332(02)01493-9

M3 - Article

VL - 210

SP - 134

EP - 139

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

IS - 1-2 SPEC.

ER -