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Published on: August 12, 2013
Fundamental aspects of quantum Brownian motion
Peter Hänggi1, Gert-Ludwig Ingold
1Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany.
This study explores quantum noise in thermal equilibrium and nonequilibrium systems. It details quantum dissipation and fluctuations using quantum Langevin equations and path integrals, revealing insights into open quantum dynamics.
Area of Science:
- Quantum physics
- Statistical mechanics
Background:
- The quantum fluctuation-dissipation theorem is central to understanding systems in thermal equilibrium.
- Open quantum systems exhibit dissipation and fluctuations, crucial for their dynamics.
Purpose of the Study:
- To elaborate on the physics of quantum noise in thermal equilibrium and stationary nonequilibrium.
- To discuss consequences of the quantum fluctuation-dissipation theorem for open, dissipative quantum systems.
- To investigate quantum dissipation and fluctuations using various theoretical approaches.
Main Methods:
- Application of the quantum fluctuation-dissipation theorem.
- Analysis of a damped harmonic quantum oscillator.
- Utilizing the nonlinear generalized quantum Langevin equation.
- Employing the path integral approach.
- Examining time-reversal symmetry in open quantum dynamics.
Main Results:
- Consequences of the quantum fluctuation-dissipation theorem for open systems in equilibrium are detailed.
- Quantum dissipation and fluctuations are exemplified by a damped harmonic oscillator.
- The study highlights subtleties and potential pitfalls in open quantum dynamics.
- Path integral methods are applied to metastable state decay influenced by quantum Brownian noise.
Conclusions:
- The work provides a comprehensive analysis of quantum noise in equilibrium and nonequilibrium systems.
- It clarifies the roles of quantum dissipation and fluctuations in open quantum systems.
- The findings offer insights into the behavior of quantum systems under dissipative and noisy conditions.
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