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Nuclear Feedback in a Single Electron-Charged Quantum Dot under Pulsed Optical Control
- Source :
- Proc. SPIE 7948, Advances in Photonics of Quantum Computing, Memory, and Communication IV, 79480U (2011)
- Publication Year :
- 2010
-
Abstract
- Electron spins in quantum dots under coherent control exhibit a number of novel feedback processes. Here, we present experimental and theoretical evidence of a feedback process between nuclear spins and a single electron spin in a single charged InAs quantum dot, controlled by the coherently modified probability of exciting a trion state. We present a mathematical model describing competition between optical nuclear pumping and nuclear spin-diffusion inside the quantum dot. The model correctly postdicts the observation of a hysteretic sawtooth pattern in the free-induction-decay of the single electron spin, hysteresis while scanning a narrowband laser through the quantum dot's optical resonance frequency, and non-sinusoidal fringes in the spin echo. Both the coherent electron-spin rotations, implemented with off-resonant ultrafast laser pulses, and the resonant narrow-band optical pumping for spin initialization interspersed between ultrafast pulses, play a role in the observed behavior. This effect allows dynamic tuning of the electron Larmor frequency to a value determined by the pulse timing, potentially allowing more complex coherent control operations.<br />Comment: 15 pages, 7 figures. Corrected and expanded discussion. Now includes analysis of spin-echo and optical pumping experiments, in addition to FID
- Subjects :
- Quantum Physics
Condensed Matter - Mesoscale and Nanoscale Physics
Subjects
Details
- Database :
- arXiv
- Journal :
- Proc. SPIE 7948, Advances in Photonics of Quantum Computing, Memory, and Communication IV, 79480U (2011)
- Publication Type :
- Report
- Accession number :
- edsarx.1008.0912
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1117/12.873978