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Exact decoherence to pointer states in free open quantum systems is universal.
1Institut für Physik, Universität Potsdam, Am Neuen Palais 10, D-14469 Potsdam, Germany.
Physical Review Letters
|July 13, 2004
Summary
Exact decoherence to minimal uncertainty Gaussian pointer states is a generic property for damped quantum particles. This quantum decoherence occurs regardless of initial conditions, temperature, or coupling strength, indicating a universal behavior.
Area of Science:
- Quantum mechanics
- Statistical mechanics
- Condensed matter physics
Background:
- Quantum decoherence describes the loss of quantum coherence due to environmental interactions.
- Minimal uncertainty states represent the quantum states with the lowest possible uncertainty product.
Purpose of the Study:
- To investigate the generic nature of decoherence to minimal uncertainty Gaussian pointer states for free quantum particles coupled to a heat bath.
- To determine if this decoherence is independent of initial conditions, temperature, and coupling parameters.
Main Methods:
- Analysis of damped free particles linearly coupled to a heat bath.
- Consideration of arbitrary temperatures, coupling strengths, and spectral densities (Ohmic, sub-Ohmic, supra-Ohmic).
- Examination of product initial conditions.
Main Results:
- Exact decoherence to minimal uncertainty Gaussian pointer states is shown to be a generic property.
- A critical time t(c) exists, after which the system's state is exactly representable as a mixture of Gaussian states.
- This phenomenon is independent of the initial state, temperature, and coupling details.
Conclusions:
- The exact localization into Gaussian pointer states is a universal characteristic of damped free particles.
- Decoherence to these states is not limited to specific regimes like high temperature or weak damping.
- This finding highlights a fundamental aspect of quantum system-environment interactions.
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