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Transition from diffusive to ballistic dynamics for a class of finite quantum models
Robin Steinigeweg1, Heinz-Peter Breuer, Jochen Gemmer
1Fachbereich Physik, Universität Osnabrück, Barbarastrasse 7, D-49069 Osnabrück, Germany. rsteinig@uos.de
Physical Review Letters
|November 13, 2007
Summary
Excitation transport in quantum systems shows scale-dependent behavior, transitioning between diffusive and ballistic dynamics at both small and large length scales. This finding impacts our understanding of energy transfer in finite quantum systems.
Area of Science:
- Quantum mechanics
- Condensed matter physics
- Statistical mechanics
Background:
- Investigating excitation transport in weakly coupled quantum systems is crucial for understanding energy and charge transfer.
- Previous models often assumed scale-invariant transport behaviors.
Purpose of the Study:
- To explore the dynamics of excitation probability transport in finite quantum systems.
- To determine the influence of length scales on transport behavior.
Main Methods:
- Utilized the time-convolutionless projection operator technique.
- Verified findings through numerical solutions of the time-dependent Schrödinger equation via exact diagonalization.
Main Results:
- Demonstrated that excitation transport dynamics are scale-dependent.
- Observed a transition from diffusive to ballistic transport at both small and large length scales.
- The distinction between diffusive and ballistic transport is a scale-dependent concept.
Conclusions:
- Excitation transport in finite quantum systems is not universally characterized by a single transport regime.
- The observed scale-dependent transitions highlight the complexity of energy transfer mechanisms.
- Findings necessitate re-evaluation of transport models in various quantum systems.
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