Qubit decoherence
Howard E. Brandt · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1997
We first review the mathematical physics of quantum decoherence in generic single-qubit devices, including environmental interactions. Next, we formulate the persistence probability for a qubit device as the probability of measuring the qubit device in the unperturbed state without the decoherence arising from environmental interactions. The decoherence time can be obtained from the persistence probability. Drawing on recent work of Garg, and also Palma, Suomine, and Ekert, we apply the persistence probability formalism to a generic single-qubit device coupled to a thermal environment, and also apply it to a trapped-ion quantum register coupled to the ion vibrational modes.