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Entanglement Structure of Non-Gaussian States and How to Measure It
Henry Froland1, Torsten V Zache2,3, Robert Ott2,3
1University of Washington, InQubator for Quantum Simulation (IQuS), Department of Physics, Seattle, Washington 98195, USA.
Physical Review Letters
|August 12, 2025
Summary
New quantum state characterization methods use measured correlations to reveal entanglement structure. This approach aids in studying quantum many-body phenomena and thermalization dynamics in quantum simulators.
Area of Science:
- Quantum physics
- Quantum information science
- Condensed matter physics
Background:
- Quantum simulators are advancing, necessitating advanced methods for characterizing complex quantum states.
- Understanding quantum many-body phenomena requires precise state characterization.
Purpose of the Study:
- To develop a novel protocol for constraining and characterizing quantum states using experimental correlation functions.
- To enable the measurement of a quantum state's entanglement structure.
Main Methods:
- Developed a protocol that constrains quantum states via experimentally measured correlation functions.
- Extended Gaussian state parameterizations by incorporating higher-order correlations.
- Applied the protocol to weakly interacting fermions as a proof of concept.
Main Results:
- The protocol successfully measures quantum state entanglement structure.
- The method is compatible with current and future experimental quantum simulation capabilities.
- The lowest-order expansion quantitatively predicts early-time thermalization dynamics.
Conclusions:
- The presented protocol offers a new route to study entanglement-related phenomena in quantum systems.
- The method can signal the onset of quantum chaos through the entanglement Hamiltonian.
- This work enhances the characterization of quantum states in complex many-body systems.
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