Imaging electron waves

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

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

One can image the coherent flow of electron waves through a quantum point contact (QPC) into a two-dimensional electron gas by using scanning probe microscopy. A negatively charged tip depletes the electron gas below, backscatters electron waves, and reduces the QPC conductance. By raster scanning the tip over the sample, an image of electron flow is obtained. Images at liquid He temperatures show the individual quantum modes of the QPC. At greater distances, the electron flow forms narrow branches caused by small-angle scattering. Interference fringes in the images demonstrate the coherence of electron flow. An electron interferometer that acts as a quantum phase shifter was constructed by adding a gate to reflect electron waves back to the QPC, producing a V-shaped path for interfering electron waves with the apex at the QPC. When the length of one leg of the V is altered by changing the reflector gate voltage, the fringes at the other end of the V, under the tip, shift by the same distance. The interferometer is sensitive to transit time differences as small as ∼0.1ps between the two electron paths. These observations are in good agreement with theoretical simulations of electron flow.

Original languageEnglish (US)
Pages (from-to)63-69
Number of pages7
JournalPhysica E: Low-Dimensional Systems and Nanostructures
Volume24
Issue number1-2 SPEC. ISS.
DOIs
StatePublished - Aug 2004
Externally publishedYes

Fingerprint

Imaging techniques
Electrons
Point contacts
electrons
electron gas
Interferometers
interferometers
raster scanning
electron trajectories
Scanning probe microscopy
Electron gas
Two dimensional electron gas
transit time
Phase shifters
reflectors
apexes
microscopy
interference
Scattering
Scanning

Keywords

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

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Westervelt, R. M., Topinka, M. A., Leroy, B. J., Bleszynski, A. C., Aidala, K., Shaw, S. E. J., ... Gossard, A. C. (2004). Imaging electron waves. Physica E: Low-Dimensional Systems and Nanostructures, 24(1-2 SPEC. ISS.), 63-69. https://doi.org/10.1016/j.physe.2004.04.025

Imaging electron waves. / Westervelt, R. M.; Topinka, M. A.; Leroy, Brian J; Bleszynski, A. C.; Aidala, K.; Shaw, S. E J; Heller, E. J.; Maranowski, K. D.; Gossard, A. C.

In: Physica E: Low-Dimensional Systems and Nanostructures, Vol. 24, No. 1-2 SPEC. ISS., 08.2004, p. 63-69.

Research output: Contribution to journalArticle

Westervelt, RM, Topinka, MA, Leroy, BJ, Bleszynski, AC, Aidala, K, Shaw, SEJ, Heller, EJ, Maranowski, KD & Gossard, AC 2004, 'Imaging electron waves', Physica E: Low-Dimensional Systems and Nanostructures, vol. 24, no. 1-2 SPEC. ISS., pp. 63-69. https://doi.org/10.1016/j.physe.2004.04.025
Westervelt RM, Topinka MA, Leroy BJ, Bleszynski AC, Aidala K, Shaw SEJ et al. Imaging electron waves. Physica E: Low-Dimensional Systems and Nanostructures. 2004 Aug;24(1-2 SPEC. ISS.):63-69. https://doi.org/10.1016/j.physe.2004.04.025
Westervelt, R. M. ; Topinka, M. A. ; Leroy, Brian J ; Bleszynski, A. C. ; Aidala, K. ; Shaw, S. E J ; Heller, E. J. ; Maranowski, K. D. ; Gossard, A. C. / Imaging electron waves. In: Physica E: Low-Dimensional Systems and Nanostructures. 2004 ; Vol. 24, No. 1-2 SPEC. ISS. pp. 63-69.
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