We present an adiabatic approach to the design of entangling quantum operations with two electron spins localized in separate InAs/GaAs quantum dots via the Coulomb interaction between optically-excited localized states. Slowly-varying optical pulses minimize the pulse noise and the relaxation of the excited states. An analytic "dressed state" solution gives a clear physical picture of the entangling process, and a numerical solution is used to investigate the error dynamics. For two vertically-stacked quantum dots we show that, for a broad range of dot parameters, a two-spin state with concurrence C>0.85 can be obtained by four optical pulses with durations ∼0.1−1 ns.
@article{arxiv.0802.1527,
title = {Adiabatic optical entanglement between electron spins in separate quantum dots},
author = {S. K. Saikin and C. Emary and D. G. Steel and L. J. Sham},
journal= {arXiv preprint arXiv:0802.1527},
year = {2008}
}