par Esposito, Massimiliano 
;Haake, Fritz
Référence Physical review. A, Atomic, Molecular, and Optical Physics, 72, 6, page (1-9), 063808
Publication Publié, 2005-12
;Haake, FritzRéférence Physical review. A, Atomic, Molecular, and Optical Physics, 72, 6, page (1-9), 063808
Publication Publié, 2005-12
Article révisé par les pairs
| Résumé : | A quantum system weakly interacting with a fast environment usually undergoes a relaxation with complex frequencies whose imaginary parts are damping rates quadratic in the coupling to the environment in accord with Fermi's "golden rule." We show for various models (spin damped by harmonic-oscillator or random-matrix baths, quantum diffusion, and quantum Brownian motion) that upon increasing the coupling up to a critical value still small enough to allow for weak-coupling Markovian master equations, a different relaxation regime can occur. In that regime, complex frequencies lose their real parts such that the process becomes overdamped. Our results call into question the standard belief that overdamping is exclusively a strong coupling feature. © 2005 The American Physical Society. |
