Single quantum dot nanowire photodetectors

Newly fabricated devices are a step toward quantum computing

2010-12-15

(Press-News.org) Washington, D.C. (December 14, 2010) -- Moving a step closer toward quantum computing, a research team in the Netherlands recently fabricated a photodetector based on a single nanowire, in which the active element is a single quantum dot with a volume of a mere 7,000 cubic nanometers. The device is described in the American Institute of Physics' journal Applied Physics Letters.

Photodetectors based on single quantum dots are expected to find uses in optoelectrical interfaces in future quantum computers, where single photons will carry information over long distances and single electrons will be used for computation.

"Our research team fabricated a very localized light detector with dimensions far below the wavelength of light, which enables detection with very high spatial resolution," explains Val Zwiller of the Kavli Institute of Nanoscience at Delft University of Technology.

"In addition, because quantum dots have discrete energy levels, only light in resonance with the energy levels of the quantum dot will be detected. The indium phosphide (InP) nanowire was grown with standard epitaxial techniques and the quantum dot was obtained by sandwiching a thin segment in between with a lower bandgap. We created the device using electron beam lithography to contact a single nanowire."

INFORMATION:

The article, "Single quantum dot nanowire photodetectors" by M. P. van Kouwen, M. H. M. van Weert, M. E. Reimer, N. Akopian, U. Perinetti, R. E. Algra, E. P. A. M. Bakkers, L. P. Kouwenhoven, and V. Zwiller appears in the journal Applied Physics Letters. See: http://link.aip.org/link/applab/v97/i11/p113108/s1

Journalists may request a free PDF of this article by contacting jbardi@aip.org

NOTE: An image is available for journalists. Please contact jbardi@aip.org

CAPTION: This image shows the photocurrent from the nanowire detector (the yellow spot represents the region where current is generated under illumination) and the electrical contacts are indicated in blue, while the nanowire is indicated in green.

ABOUT APPLIED PHYSICS LETTERS

Applied Physics Letters, published by the American Institute of Physics, features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, Applied Physics Letters offers prompt publication of new experimental and theoretical papers bearing on applications of physics phenomena to all branches of science, engineering, and modern technology. Content is published online daily, collected into weekly online and printed issues (52 issues per year). See: http://apl.aip.org/

ABOUT AIP

The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world's largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.

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Single quantum dot nanowire photodetectors

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