https://doi.org/10.1140/epjd/e2010-00183-7
State transfer in dissipative and dephasing environments
School of Science, Xi'an University of Posts and Telecommunications, Xi'an, 710061, P.R. China
Corresponding author: a mingliang0301@xupt.edu.cn
Received:
16
January
2010
Revised:
14
April
2010
Published online:
6
July
2010
By diagonalization of a generalized superoperator for
solving the master equation, we investigated effects of dissipative
and dephasing environments on quantum state transfer, as well as
entanglement distribution and creation in spin networks. Our results
revealed that under the condition of the same decoherence rate
γ, the detrimental effects of the dissipative environment are
more severe than that of the dephasing environment. Beside this, the
critical time tc at which the transfer fidelity and the
concurrence attain their maxima arrives at the asymptotic value
t0 = π/2λ quickly as the spin chain length N increases.
The transfer fidelity of an excitation at time t0 is independent
of N when the system subjects to dissipative environment, while it
decreases as N increases when the system subjects to dephasing
environment. The average fidelity displays three different patterns
corresponding to N = 4r + 1, N = 4r-1 and N = 2r. For each pattern,
the average fidelity at time t0 is independent of r when the
system subjects to dissipative environment, and decreases as r
increases when the system subjects to dephasing environment. The
maximum concurrence also decreases as N increases, and when
N ∞, it arrives at an asymptotic value determined
by the decoherence rate γ and the structure of the spin
network.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2010