We propose to develop a novel photon detector for applications in quantum information processing
and for general applications in areas where detection of ultra weak photon fluxes is required.
The proposal addresses the demand in quantum information processing for a single photon detector
that can discriminate between different numbers of photons in a light pulse. The detector represents
a new type of optoelectronic nanocircuit on GaAs that employs charge transport by surface acoustic waves.
Operation of the detector is based on measurement of a number of electrons and the holes created in a
semiconductor layer by a light pulse. The detector exploits the charge transport by surface acoustic
waves in order to realize a design in which a big photon absorption area (providing a high photon
collection efficiency) is spatially separated from a microscopically small charge detection area
(providing the sensitivity of charge measurement at the single electron level). The proposed design
facilitates achieving a high quantum efficiency of the detector.
An important objective of the program is the characterization and optimization of the process of
acoustic charge transport (ACT). During the work we plan to develop very sensitive techniques for
characterization of the ACT fidelity and to explore the mechanisms that control it.
The fidelity will be quantified in the terms of the length that the SAW can travel without changing
the amount of charge residing in its potential minima. There exist proposals of employing the ACT
for quantum information processing, and we believe that the ACT will have a wider-ranging relevance
than the present program may imply.
Further information:
Dr. Per Delsing,
Quantum Device Physics Laboratory,
Microtechnology and Nanoscience,
Chalmers University of Technology,
SE-412 96 Göteborg,
Sweden.
Tel: +46-31-772 3317,
Fax: +46-31-772 3442,
E-mail:
per.delsing@chalmers.se
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