Physics – Quantum Physics
Scientific paper
2006-07-31
Physics
Quantum Physics
12 PR pages, 8 figures
Scientific paper
10.1088/0305-4470/39/44/008
We study the Landau-Zener Problem for a decaying two-level-system described by a non-hermitean Hamiltonian, depending analytically on time. Use of a super-adiabatic basis allows to calculate the non-adiabatic transition probability P in the slow-sweep limit, without specifying the Hamiltonian explicitly. It is found that P consists of a ``dynamical'' and a ``geometrical'' factors. The former is determined by the complex adiabatic eigenvalues E_(t), only, whereas the latter solely requires the knowledge of \alpha_(+-)(t), the ratio of the components of each of the adiabatic eigenstates. Both factors can be split into a universal one, depending only on the complex level crossing points, and a nonuniversal one, involving the full time dependence of E_(+-)(t). This general result is applied to the Akulin-Schleich model where the initial upper level is damped with damping constant $\gamma$. For analytic power-law sweeps we find that Stueckelberg oscillations of P exist for gamma smaller than a critical value gamma_c and disappear for gamma > gamma_c. A physical interpretation of this behavior will be presented by use of a damped harmonic oscillator.
Garanin Dmitry A.
Schilling Rene
Vogelsberger Mark
No associations
LandOfFree
Nonadiabatic Transitions for a Decaying Two-Level-System: Geometrical and Dynamical Contributions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Nonadiabatic Transitions for a Decaying Two-Level-System: Geometrical and Dynamical Contributions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonadiabatic Transitions for a Decaying Two-Level-System: Geometrical and Dynamical Contributions will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-33655