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Updated: Apr 7, 2026
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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
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Thermalization of entanglement.
Liangsheng Zhang1, Hyungwon Kim1,2, David A Huse1
1Physics Department, Princeton University, Princeton, New Jersey 08544, USA.
Summary
We studied entanglement entropy dynamics in quantum spin chains. Slow relaxation in Hamiltonian systems is linked to energy transport, unlike in Floquet systems.
Area of Science:
- Quantum information theory
- Condensed matter physics
- Statistical mechanics
Background:
- Entanglement entropy quantifies quantum correlations in many-body systems.
- Understanding the dynamics of entanglement entropy is crucial for characterizing thermalization and quantum chaos.
- Highly entangled pure states in quantum chaotic systems provide a unique platform to study these dynamics.
Purpose of the Study:
- To investigate the dynamics of entanglement entropy near equilibrium in two quantum-chaotic spin chains.
- To compare the relaxation and fluctuation dynamics between a system with a time-independent Hamiltonian and a Floquet system.
- To identify the underlying mechanisms responsible for the observed relaxation behavior.
Main Methods:
- Unitary time evolution of highly entangled pure states in quantum-chaotic spin chains.
- Analysis of entanglement entropy relaxation from initial states with varying entanglement.
- Examination of spontaneous entanglement fluctuations in equilibrium.
- Comparison between a Hamiltonian spin chain and a Floquet spin chain.
Main Results:
- Slow relaxation of entanglement entropy near equilibration was observed in the Hamiltonian spin chain.
- This slow relaxation was absent in the Floquet spin chain.
- Spontaneous fluctuations of entanglement entropy in equilibrium were also analyzed.
- The presence of a local conservation law (extensive conserved energy) in the Hamiltonian system was noted.
Conclusions:
- Slow diffusive energy transport is identified as the cause for slow entanglement entropy relaxation in the Hamiltonian system.
- The absence of slow relaxation in the Floquet system is attributed to the lack of a local conservation law.
- These findings highlight the role of conservation laws and energy transport in the thermalization dynamics of quantum systems.
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