2006/02/28 by D. D. Bhaktavatsala Rao, V. Ravishankar, V. Subrahmanyam
Computer Science · Physics and Astronomy · #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum optics and atomic interactions #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physreva.74.022301
published as Phys. Rev. A 74, 022301 (2006) · 11 pages, 6 figures Accepted for publication in Phys.Rev A
arxiv created 2006/07/12 · openalex publication_date 2006/08/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The dynamics of a spin-1∕2 particle coupled to a nuclear spin bath through an isotropic Heisenberg interaction is studied as a model for the spin decoherence in quantum dots. The time-dependent polarization of the central spin is calculated as a function of the bath-spin distribution and the polarizations of the initial bath state. For short times, the polarization of the central spin shows a Gaussian decay, and at later times it is revived displaying nonmonotonic time dependence. The decoherence time scale depends on moments of the bath-spin distribuition, and also on the polarization strengths in various bath-spin channels. The bath polarizations have a tendency to increase the decoherence time scale. The effective dynamics of the central spin polarization is shown to be described by a master equation with non-Markovian features.