Fast quantum noise in the Landau-Zener transition
Loading...
Date
2007
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
American Physical Society
Abstract
We show by direct calculation starting from a microscopic model that the two-state system with time-dependent energy levels in the presence of fast quantum noise obeys the master equation. The solution of master equation is found analytically and analyzed in a broad range of parameters. The fast transverse noise affects the transition probability during much longer time (the accumulation time) than the longitudinal one. The action of the fast longitudinal noise is restricted by the shorter Landau-Zener time, the same as in the regular Landau-Zener process. The large ratio of time scales allows solving the Landau-Zener problem with longitudinal noise only, and then solving the same problem with the transverse noise only and matching the two solutions. The correlation of the longitudinal and transverse noise renormalizes the Landau-Zener transition matrix element and can strongly enhance the survival probability, whereas the transverse noise always reduces it. If the noise is fast, its intensity at which the multiquantum processes become essential corresponds to a deeply adiabatic regime. We briefly discuss possible applications of the general theory to the molecular magnets.
Description
Journals published by the American Physical Society can be found at http://journals.aps.org/
Keywords
SURVIVAL PROBABILITY, 2-STATE SYSTEM, DYNAMICS, MODEL, OSCILLATOR, Physics
Citation
Valery L. Pokrovsky and D. Sun. Phys.Rev.B 76 024310 2007."Copyright (2007) by the American Physical Society."