Fast noise in the Landau-Zener theory

نویسندگان

  • V. L. Pokrovsky
  • N. A. Sinitsyn
چکیده

We study the influence of a fast noise on Landau-Zener transitions. We demonstrate that a fast colored noise much weaker than the conventional white noise can produce transitions itself or can change substantially the Landau-Zener transition probabilities. In the limit of fast colored or strong white noise we derive asymptotically exact formulas for transition probabilities and study the time evolution of a spin coupled to the noise and a sweeping magnetic field.

منابع مشابه

Fast quantum noise in the Landau-Zener transition

We show by direct calculation starting from a microscopic model that the two-state system with timedependent 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 tha...

متن کامل

Investigation of Temperature Effect in Landau-Zener Avoided Crossing

Considering a temperature dependent two-level quantum system, we have numerically solved the Landau-Zener transition problem. The method includes the incorporation of temperature effect as a thermal noise added Schrödinger equation for the construction of the Hamiltonian. Here, the obtained results which describe the changes in the system including the quantum states and the transition pro...

متن کامل

Noise effect on the nonadiabatic transition and correction to the tunneling energy gap estimated by the Landau-Zener-Stückelberg formula

We study effect of noise on the tunneling process of the magnetization in a sweeping field from the viewpoint of the nonadiabatic transition. The tunneling probability depends on the properties of the noise, e.g. the direction, the amplitude, and the relaxation time of the autocorrelation function. We investigate the tunneling process in the presence of noise by solving the time-dependent Schrö...

متن کامل

Nonlinear Landau-Zener tunneling in quantum phase space

We present a detailed analysis of the Landau-Zener problem for an interacting Bose-Einstein condensate in a time-varying double-well trap, especially focussing on the relation between the full many-particle problem and the mean-field approximation. Due to the nonlinear self-interaction a dynamical instability occurs, which leads to a breakdown of adiabaticity condition and thus fundamentally al...

متن کامل

Correlations in noisy Landau-Zener transitions

We analyze the influence of colored classical Gaussian noise on Landau-Zener transitions during a two-level crossing in a time-dependent regular external field. Transition probabilities and coherence factors become random due to the noise. We calculate their two-time correlation functions, which describe the response of this two-level system to a weak external pulse signal. The spectrum and int...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

متن کامل
عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2002