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arXiv · 2407.12083

Entanglement Structure of Non-Gaussian States and How to Measure It

Henry Froland·Torsten V. Zache·Robert Ott·Niklas Mueller
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Abstract

Rapidly growing capabilities of quantum simulators to probe quantum many-body phenomena require new methods to characterize increasingly complex states. We present a protocol that constrains quantum states by experimentally measured correlation functions which only scales polynomially with system size. This method enables measurement of a quantum state's entanglement structure, opening a new route to study entanglement-related phenomena. Our approach extends Gaussian state parameterizations by systematically incorporating higher-order correlations. We show the protocol's usefulness in conjunction with current and forthcoming experimental capabilities, focusing on weakly interacting fermions as a proof of concept. Here, the lowest non-trivial expansion quantitatively predicts early time thermalization dynamics, including signaling the on-set of quantum chaos indicated by the entanglement Hamiltonian.

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Henry Froland, Torsten V. Zache, Robert Ott, Niklas Mueller. 2024-07-16. Entanglement Structure of Non-Gaussian States and How to Measure It. https://arxiv.org/abs/2407.12083

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