Typical entanglement entropy with charge conservation

Abstract:We consider a many-body Hilbert space with a fixed global charge and show that the typical entanglement entropy of a subsystem, at the leading and subleading order in the thermodynamic limit, can be expressed in terms of a single quantity which represents the local thermal entropy at fixed charge density. We find a general formula which applies both to abelian U(1) symmetry and non-abelian SU(2) symmetry, including the case of a local Hilbert space which transforms under a general reducible representation of the symmetry group. We illustrate the general formula with model systems and discuss the relevance of the results as a probe of quantum chaos for physical Hamiltonians.

Quantum Physics (quant-ph); Statistical Mechanics (cond-mat.stat-mech); General Relativity and Quantum Cosmology (gr-qc)

arXiv:2604.26141 [quant-ph]

(or arXiv:2604.26141v2 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2604.26141 Focus to learn more arXiv-issued DOI via DataCite

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