title: Picosecond coherent optical manipulation of a single electron spin in a quantum dot.
abstract: 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.
authors.affiliation: Center for Spintronics and Quantum Computation, University of California, Santa Barbara, CA 93106, USA.
authors.forename: J
authors.initials: J
authors.lastname: Berezovsky
authors.forename: M H
authors.initials: MH
authors.lastname: Mikkelsen
authors.forename: N G
authors.initials: NG
authors.lastname: Stoltz
authors.forename: L A
authors.initials: LA
authors.lastname: Coldren
authors.forename: D D
authors.initials: DD
authors.lastname: Awschalom