4 research outputs found
Entanglement with phase decoherence
The system of an atom couples to two distinct optical cavities with phase
decoherence is studied by making use of a dynamical algebraic method. We adopt
the concurrence to characterize the entanglement between atom and cavities or
between two optical cavities in the presence of the phase decoherence. It is
found that the entanglement between atom and cavities can be controlled by
adjusting the detuning parameter. Finally, we show that even if the atom is
initially prepared in a maximally mixed state, it can also entangle the two
mode cavity fields.Comment: 9 pages, 6 figures, lete
Qubit Disentanglement and Decoherence via Dephasing
We consider whether quantum coherence in the form of mutual entanglement
between a pair of qubits is susceptible to decay that may be more rapid than
the decay of the coherence of either qubit individually. An instance of
potential importance for solid state quantum computing arises if embedded
qubits (spins, quantum dots, Cooper pair boxes, etc.) are exposed to global and
local noise at the same time. Here we allow separate phase-noisy channels to
affect local and non-local measures of system coherence. We find that the time
for decay of the qubit entanglement can be significantly shorter than the time
for local dephasing of the individual qubits.Comment: REVTeX, 9 pages, 1 figure, v2 with minor changes, reference adde