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Dephasing and the steady state in quantum many-particle systems
1Institute for Theoretical Physics C, RWTH Aachen, D-52056 Aachen, Germany.
Physical Review Letters
|March 21, 2008
Summary
We explore how many-particle systems relax, finding that dephasing creates steady states in finite subsystems. This work also shows how parameter quenches can controllably generate strong entanglement.
Area of Science:
- Quantum many-body physics
- Statistical mechanics
Background:
- Understanding relaxation dynamics in isolated quantum systems is crucial.
- Integrable systems present unique challenges and behaviors in thermalization and dephasing.
Purpose of the Study:
- To investigate relaxation mechanisms in bosonic and fermionic many-particle systems.
- To derive steady states of finite subsystems under time evolution.
- To identify conditions for effective dephasing and its limitations.
Main Methods:
- Explicit derivation of steady subsystem states.
- Analysis of dephasing effects in various system dimensions and criticalities.
- Study of entanglement entropy evolution after parameter quenches.
Main Results:
- Identified dephasing as a mechanism leading to steady states in finite subsystems of integrable systems.
- Determined sufficient conditions for dephasing and found scenarios where it is ineffective.
- Demonstrated that entanglement entropy becomes extensive after parameter quenches.
Conclusions:
- Dephasing provides a pathway to controllable steady states in specific quantum systems.
- Parameter quenches offer a method for generating significant entanglement in a controlled manner.
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