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Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
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Reversibility of dynamics and multiple-quantum coherences.
1Department of Chemistry, Kent State University, Kent, Ohio 44242, USA.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|December 15, 2015
Summary
The Loschmidt echo decay in time-reversal experiments is tied to multiple-quantum coherences. This study defines criteria for weak irreversibility in quantum dynamics, applicable beyond spin systems.
Area of Science:
- Quantum physics
- Condensed matter physics
- Statistical mechanics
Background:
- The Loschmidt echo measures the sensitivity of quantum systems to perturbations.
- Multiple-quantum (MQ) coherences arise in complex quantum systems and are linked to dynamics.
- Irreversibility in quantum dynamics is a fundamental concept with implications for thermodynamics.
Purpose of the Study:
- To establish a link between Loschmidt echo decay and the generation of MQ coherences.
- To formulate criteria for weak irreversibility in quantum dynamics.
- To generalize the analysis of quantum dynamics reversibility beyond spin systems.
Main Methods:
- Analysis of the Loschmidt echo in time-reversal experiments.
- Investigation of the growth of multiple-quantum coherences.
- Formulation of criteria for weak irreversibility based on linear time dependence.
Main Results:
- The decay of the Loschmidt echo is directly related to the generation of MQ coherences.
- Unlimited growth of MQ coherences leads to irreversible dynamics.
- Criteria for weak irreversibility are established, characterized by linear time dependence of specific observables.
Conclusions:
- The study provides a framework for understanding irreversibility in quantum systems.
- The proposed approach offers a method to analyze reversibility in many-body quantum dynamics.
- The findings have potential applications in various quantum systems beyond spins.
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