Abstract
We study spin dynamics and singlet-triplet decoherence due to the hyperfine interaction in a parabolic double quantum dot. We use exact diagonalization and perturbation theory for calculating the time evolution of the wave function. The probabilities for the singlet state exhibit damped oscillations and converge toward a value, which depends only on the strength of the hyperfine field and the exchange energy. We derive expressions for the asymptotic singlet probability and its variance using a effective Hamiltonian matrix. The asymptotic values and variances for singlet probabilities are in agreement with previous experimental data.
- Received 2 April 2008
DOI:https://doi.org/10.1103/PhysRevB.77.245315
©2008 American Physical Society