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arXiv · 2303.02130

Towards Entanglement Entropy of Random Large-N Theories

Siqi Shao·Yashar Komijani
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Abstract

A large class of strongly correlated quantum systems can be described in certain large-N limits by quadratic in field actions along with self-consistency equations that determine the two-point functions. We use the replica approach and the notion of shifted Matsubara frequency to compute von Neumann and R\'enyi entanglement entropies for generic bi-partitioning of such systems. We argue that the von Neumann entropy can be computed from equilibrium spectral functions w/o partitioning, while the R\'enyi entropy requires re-calculating the spectrum in the interacting case. We demonstrate the flexibility of the method by applying it to examples of a two-site problem in presence of decoherence, and coupled Sachdev-Ye-Kitaev models.

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Siqi Shao, Yashar Komijani. 2023-03-03. Towards Entanglement Entropy of Random Large-N Theories. https://doi.org/10.1103/physrevd.109.016015

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