Quantum Brownian motion in a bath of parametric oscillators: A model for system-field interactions
- Department of Physics, University of Maryland, College Park, Maryland 20742 (United States)
- Department of Physics, University of Adelaide, 5005 (Australia)
The quantum Brownian motion paradigm provides a unified framework where one can see the interconnection of some basic quantum statistical processes such as decoherence, dissipation, particle creation, noise, and fluctuation. The present paper continues the investigation begun in earlier papers on the quantum Brownian motion in a general environment via the influence functional formalism. Here, the Brownian particle is coupled linearly to a bath of the most general time-dependent quadratic oscillators. This bath of parametric oscillators minics a scalar field, while the motion of the Brownian particle modeled by a single oscillator could be used to depict the behavior of a particle detector, a quantum field mode, or the scale factor of the Universe. An important result of this paper is the derivation of the influence functional encompassing the noise and dissipation kernels in terms of the Bogolubov coefficients, thus setting the stage for the influence functional formalism treatment of problems in quantum field theory in curved spacetime. This method enables one to trace the source of statistical processes such as decoherence and dissipation to vacuum fluctuations and particle creation, and in turn impart a statistical mechanical interpretation of quantum field processes. With this result we discuss the statistical mechanical origin of quantum noise and thermal radiance from black holes and from uniformly accelerated observers in Minkowski space as well as from the de Sitter universe discovered by Hawking, Unruh, and Gibbons and Hawking. We also derive the exact evolution operator and master equation for the reduced density matrix of the system interacting with a parametric oscillator bath in an initial squeezed thermal state. These results are useful for decoherence and back reaction studies for systems and processes of interest in semiclassical cosmology and gravity. Our model and results are also expected to be useful for related problems in quantum optics.
- OSTI ID:
- 7116955
- Journal Information:
- Physical Review, D (Particles Fields); (United States), Vol. 49:12; ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
OSCILLATORS
BROWNIAN MOVEMENT
DISSIPATION FACTOR
FLUCTUATIONS
MINKOWSKI SPACE
NOISE
PARTICLE PRODUCTION
SCALAR FIELDS
SPACE-TIME
TIME DEPENDENCE
UNIVERSE
ELECTRONIC EQUIPMENT
EQUIPMENT
MATHEMATICAL SPACE
SPACE
VARIATIONS
661300* - Other Aspects of Physical Science- (1992-)
661100 - Classical & Quantum Mechanics- (1992-)