Turkish Journal of PhysicsTowards Quantum Communication with Electron Spins
P. RECHER1, D. LOSS1
1Department of Physics and Astronomy, University of Basel
Klingelbergstrasse 82, 4056 Basel, Switzerland
2IBM T. J. Watson Research Center, P. O. Box 218,
Yorktown Heights, NY 10598
3Department of Physics and Informatics, University of
São Paulo at São Carlos, 13560-970 São Carlos/SP, Brazil
Abstract: We review our recent work towards quantum communication in a solid-state environment with qubits carried by electron spins. We propose three schemes to produce spin-entangled electrons, where the required separation of the partner electrons is achieved via Coulomb interaction. The non-product spin-states originate either from the Cooper pairs found in a superconductor, or in the ground state of a quantum dot with an even number of electrons. In a second stage, we show how spin-entanglement carried by a singlet can be detected in a beam-splitter geometry by an increased (bunching) or decreased (antibunching) noise signal. We also discuss how a local spin-orbit interaction can be used to provide a continuous modulation of the noise as a signature of entanglement. Finally, we review how one can use a quantum dot as a spin-filter, a spin-memory read-out, a probe for single-spin decoherence and, ultimately, a single-spin measurement apparatus.
Turk. J. Phys., 27, (2003), 427-442.
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Other articles published in the same issue: Turk. J. Phys.,vol.27,iss.5.