English

Typical entanglement entropy with charge conservation

Quantum Physics 2026-04-30 v1 Statistical Mechanics General Relativity and Quantum Cosmology

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.

Keywords

Cite

@article{arxiv.2604.26141,
  title  = {Typical entanglement entropy with charge conservation},
  author = {Eugenio Bianchi and Pietro Donà and Erick Muiño},
  journal= {arXiv preprint arXiv:2604.26141},
  year   = {2026}
}

Comments

33 pages, 9 figures

R2 v1 2026-07-01T12:40:13.648Z