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Persistence of coherent quantum dynamics at strong dissipation
Denis Kast1, Joachim Ankerhold
1Institut für Theoretische Physik, Universität Ulm, Albert-Einstein-Allee 11, 89069 Ulm, Germany.
Physical Review Letters
|February 7, 2013
Summary
Quantum systems under strong friction exhibit persistent coherences, even when behaving classically. This finding challenges traditional relaxation theories and has implications for nanoscale device experiments.
Area of Science:
- Quantum mechanics
- Condensed matter physics
- Quantum information
Background:
- Investigating quantum dynamics in open systems is crucial for understanding energy dissipation and decoherence.
- Sub-Ohmic spectral densities and strong friction present unique challenges for theoretical and numerical modeling.
Purpose of the Study:
- To explore the quantum dynamics of a two-state system coupled to a sub-Ohmic bosonic reservoir under strong friction.
- To determine if a transition from coherent to incoherent relaxation occurs in this regime.
Main Methods:
- Utilized numerically exact path integral Monte Carlo methods for accurate simulations.
- Focused on systems with strong friction and sub-Ohmic spectral densities.
Main Results:
- Demonstrated that a changeover from coherent to incoherent relaxation does not occur for a broad range of spectral distributions.
- Observed persistent nonequilibrium coherences and significant system-reservoir entanglement, even under strong dissipation.
Conclusions:
- Strong dissipation does not necessarily lead to classical behavior or complete loss of quantum coherence.
- The findings are relevant for understanding quantum phenomena in nanoscale devices and quantum technologies.
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