SKM 2023 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 18: Nano- and Optomechanics
TT 18.4: Vortrag
Montag, 27. März 2023, 18:00–18:15, HSZ 201
Symmetry breaking in a parametrically modulated quantum oscillator — •Daniel Boneß1, Mark Dykman2, and Wolfgang Belzig1 — 1Department of Physics, University of Konstanz, 78457 Konstanz, Germany — 2Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
A weakly damped nonlinear oscillator modulated close to twice its eigenfrequency has two stable states, which have the same vibration amplitudes but opposite phases. The states are equally populated due to classical or quantum fluctuations.
An extra force at half the modulation frequency lifts the symmetry of the states, generally. We study how the symmetry breaking occurs in the quantum regime.
As we show, a significant change of the state populations can take place already for a weak extra force. The mechanism is the force-induced change of the rates of interstate switching. The change is exponential in the ratio of the force amplitude to the appropriately scaled quantum length. It is large even where the effect of the force on the mean-field oscillator dynamics is small.