We analyze local spin-echo procedures to protect entanglement betweentwo non-interacting qubits, each subject to pure-dephasing random telegraph noise.For superconducting qubits this simple model captures characteristic features of theeffect of bistable impurities coupled to the device. An analytic expression for theentanglement dynamics is reported. Peculiar features related to the non-Gaussiannature of the noise already observed in the single qubit dynamics also occur in theentanglement dynamics for proper values of the ratio g = v=, between the qubitimpuritycoupling strength and the switching rate of the random telegraph process,and of the separation between the pulses Δt. We find that the echo proceduremay delay the disappearance of entanglement, cancel the dynamical structure ofentanglement revivals and dark periods, and induce peculiar plateau-like behaviorsof the concurrence.
|Numero di pagine||5|
|Stato di pubblicazione||Published - 2013|
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