Noise-Induced Multilevel Landau-Zener Transitions: Density Matrix Investigation

Publication date: Available online 21 January 2019Source: Physics Letters AAuthor(s): I.F. Nyisomeh, M.E. Ateuafack, L.C. FaiAbstractThe generalised multilevel Landau-Zener problem is solved by applying the density matrix technique within the framework of nonstationary perturbation theory. The exact survival probability is achieved as a proof of the Brundobler-Elzer hypothesis [J. Phys. A: Math. Gen. 26, 1211 (1993)]. The effect of classical Gaussian noise is investigated by averaging the solution over the noise realisation. A generalised formula for slow noise-induced transition probability is obtained and found to agree exactly with all known results. Exact results are reported for the Demkov-Osherov model in the slow and fast noise limits. Thermal transition probabilities are obtained via the activation Arrhenius law and observed to tailor a qubit from thermal decoherence.

Source: Physics Letters A - January 22, 2019 Category: Physics Source Type: research