Decoherence recuperating fast environmental dynamics
Murat Çetinbaş
We examine the exact internal decoherence dynamics of a qubit in an isolated Josephson charge-qubit quantum computer in the presence of one- and two-body static internal imperfections. By help of open system dynamics quantifiers, i.e. purity, fidelity, covariance and Loschmidt echo, we distinguish between non-unitary and unitary components of internal decoherence dynamics and show that the non-unitary component consists of two processes: system-environment entanglement and incoherence. Our results indicate that the incoherence process is the major source of internal decoherence rather than system-environment entanglement. We find that strong one-body intra–environmental interactions, which generate fast environmental dynamics, result in a rapid suppression of decoherence induced by both system–environment entanglement and incoherence processes. We explain the mechanisms of suppression of decoherence for these two processes and discuss our results.
Journal of Physics A Mathematical and Theoretical•Jan 14, 2010•0 citations