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.

Science 18 April 2008:
Vol. 320. no. 5874, pp. 349 - 352
DOI: 10.1126/science.1154798
Prev | Table of Contents | Next

Reports

Picosecond Coherent Optical Manipulation of a Single Electron Spin in a Quantum Dot

J. Berezovsky,* M. H. Mikkelsen,* N. G. Stoltz, L. A. Coldren, D. D. Awschalom{dagger}

Most schemes for quantum information processing require fast single-qubit operations. For spin-based qubits, this involves performing arbitrary coherent rotations of the spin state on time scales much faster than the spin coherence time. By applying off-resonant, picosecond-scale optical pulses, we demonstrated the coherent rotation of a single electron spin through arbitrary angles up to {pi} radians. We directly observed this spin manipulation using time-resolved Kerr rotation spectroscopy and found that the results are well described by a model that includes the electronnuclear spin interaction. Measurements of the spin rotation as a function of laser detuning and intensity confirmed that the optical Stark effect is the operative mechanism.

Center for Spintronics and Quantum Computation, University of California, Santa Barbara, CA 93106, USA.

* These authors contributed equally to this work.

{dagger} To whom correspondence should be addressed. E-mail: awsch{at}physics.ucsb.edu

Read the Full Text

To Advertise     Find Products

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