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Entanglement Growth from Entangled States: A Unified Perspective on Entanglement Generation and Transport
Chun-Yue Zhang1,2, Zi-Xiang Li1,2, Shi-Xin Zhang1
1Chinese Academy of Sciences, Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Beijing 100190, China.
Physical Review Letters
|July 26, 2026
Summary
Entanglement entropy growth in quantum systems can unexpectedly decrease with more initial entanglement. A new "build-move" framework explains this by separating entanglement creation from redistribution, crucial for understanding quantum information.
Area of Science:
- Quantum Many-Body Physics
- Quantum Information Science
- Condensed Matter Theory
Background:
- Most studies on quantum entanglement dynamics focus on simple initial states.
- Investigating dynamics from complex, entangled initial states reveals richer phenomena.
- Understanding entanglement propagation is key to quantum information processing.
Purpose of the Study:
- To explore quantum many-body entanglement dynamics starting from initial entangled states.
- To uncover universal patterns in entanglement growth across different quantum systems.
- To introduce a framework for understanding the mechanisms behind entanglement evolution.
Main Methods:
- Analysis of entanglement entropy growth in various quantum systems, including many-body localization (MBL) and random quantum circuits.
- Development of a conceptual framework decomposing entanglement growth into 'build' (creation) and 'move' (redistribution) mechanisms.
- Quantitative comparison of MBL dynamics to a random SWAP circuit model representing pure 'move' dynamics.
Main Results:
- Entanglement entropy growth shows a nonmonotonic dependence on initial entanglement in nonergodic systems, peaking at moderate initial entanglement.
- Many-body localization (MBL) dynamics are characterized as 'move-dominated', effectively redistributing existing entanglement.
- The 'build-move' framework provides a unified perspective on diverse quantum dynamics.
Conclusions:
- Initial entanglement significantly influences entanglement entropy growth in nonergodic quantum systems.
- MBL systems act as redistributors of entanglement, akin to a pure 'move' process.
- The 'build-move' framework offers novel insights into entanglement propagation and quantum information scrambling.
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