Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 8 August 2003:
Vol. 301. no. 5634, pp. 809 - 811
DOI: 10.1126/science.1083800
Prev | Table of Contents | Next

Reports

An All-Optical Quantum Gate in a Semiconductor Quantum Dot

Xiaoqin Li,1 Yanwen Wu,1 Duncan Steel,1* D. Gammon,2 T. H. Stievater,2 D. S. Katzer,2 D. Park,2 C. Piermarocchi,3 L. J. Sham4

We report coherent optical control of a biexciton (two electron-hole pairs), confined in a single quantum dot, that shows coherent oscillations similar to the excited-state Rabi flopping in an isolated atom. The pulse control of the biexciton dynamics, combined with previouslydemonstrated control of the single-exciton Rabi rotation, serves as the physical basis for a two-bit conditional quantum logic gate. The truth table of the gate shows the features of an all-optical quantum gate with interacting yet distinguishable excitons as qubits. Evaluation of the fidelity yields a value of 0.7 for the gate operation. Such experimental capabilityis essential to a scheme for scalable quantum computation bymeans of the optical control of spin qubits in dots.

1 Frontiers in Optical Coherent and Ultrafast Science (FOCUS), Harrison M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109–1120, USA.
2 Naval Research Laboratory, Washington, DC 20375–5347, USA.
3 Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824–2320, USA.
4 Department of Physics, The University of California, San Diego, La Jolla, CA 92093–0319, USA.

* To whom correspondence should be addressed. E-mail: dst{at}umich.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Two-Quantum 2D FT Electronic Spectroscopy of Biexcitons in GaAs Quantum Wells.
K. W. Stone, K. Gundogdu, D. B. Turner, X. Li, S. T. Cundiff, and K. A. Nelson (2009)
Science 324, 1169-1173
   Abstract »    Full Text »    PDF »
Conditional Dynamics of Interacting Quantum Dots.
L. Robledo, J. Elzerman, G. Jundt, M. Atature, A. Hogele, S. Falt, and A. Imamoglu (2008)
Science 320, 772-775
   Abstract »    Full Text »    PDF »
Coherent Dynamics of Coupled Electron and Nuclear Spin Qubits in Diamond.
L. Childress, M. V. Gurudev Dutt, J. M. Taylor, A. S. Zibrov, F. Jelezko, J. Wrachtrup, P. R. Hemmer, and M. D. Lukin (2006)
Science 314, 281-285
   Abstract »    Full Text »    PDF »
Quantum-Dot Spin-State Preparation with Near-Unity Fidelity.
M. Atature, J. Dreiser, A. Badolato, A. Hogele, K. Karrai, and A. Imamoglu (2006)
Science 312, 551-553
   Abstract »    Full Text »    PDF »
Optical Signatures of Coupled Quantum Dots.
E. A. Stinaff, M. Scheibner, A. S. Bracker, I. V. Ponomarev, V. L. Korenev, M. E. Ware, M. F. Doty, T. L. Reinecke, and D. Gammon (2006)
Science 311, 636-639
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)