Regensburg 2002 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

DY: Dynamik und Statistische Physik

DY 22: Quantenph
änomene

DY 22.5: Hauptvortrag

Dienstag, 12. März 2002, 12:30–13:00, H2

Bistabilitaet und Stochastische Resonanz in einem fundamentalen Quantensystem — •Andreas Buchleitner — MPI fuer Physik komplexer Systeme, Noethnitzer Str. 38, 01069 Dresden

Stochastic resonance (SR) is a paradigm of the counterintuitive role that noise can play in nonlinear systems. Assume we drive a nonlinear bistable system by a weak periodic signal which in itself is insufficient to induce a deterministic transition between the two stable states. If we add a stochastic forcing to the coherent drive, it has been shown that there is an optimal nonvanishing noise level at which the system will exhibit almost periodic transitions from one state to the other, at the frequency of the coherent signal. We (theoretically and numerically) demonstrate and analyse this effect in the response of an experimentally accessible, open, driven quantum system to a weak periodic drive. Noise-induced signal enhancement is observed in the population and in the coherence of a sequence of two level atoms interacting with a single mode of the quantized radiation field coupled to a dissipative environment.