A signature of quantumness in pure decoherence control

Abstract

We study a decoherence reduction scheme that involves an intermediate measurement on the qubit in an equal superposition basis, in the general framework of all qubit-environment interactions that lead to qubit pure decoherence. We show under what circumstances the scheme always leads to a gain of coherence on average, regardless of the time at which the measurement is performed, demonstrating its wide range of applicability. Furthermore, we find that observing an average loss of coherence is a highly quantum effect, resulting from non-commutation of different terms in the Hamiltonian. We show the diversity of behavior of coherence as effected by the application of the scheme, which is skewed towards gain rather than loss, on a variant of the spin-boson model that does not fulfill the commutation condition.

11 pages, 5 figures

References in corpus (10)

• Pure quantum dephasing of a solid state electron spin qubit in a large nuclear spin bath coupled by long-range hyperfine-mediated interactions
• Non-Markovian entanglement dynamics of noisy continuous variable quantum channels
• Universal coherence protection in a solid-state spin qubit
• Electrical Control of Coherent Spin Rotation of a Single-Spin Qubit
• "Which path" decoherence in quantum dot experiments
• Equivalence of qubit-environment entanglement and discord generation via pure dephasing interactions and the consequences thereof
• On Markovianity and classicality in multilevel spin-boson models
• Purifying teleportation
• On the classicality of quantum dephasing processes
• Statistics of projective measurement on a quantum probe as a witness of noncommutativity of algebra of a probed system

Cited by in corpus (1)

• Qubit-environment entanglement in time-dependent pure dephasing