Volume-law entanglement fragmentation of quasiparticles

Abstract

We investigate the entanglement entropy in quantum states featuring repeated sequential excitations of unit patterns in momentum space. In the scaling limit, each unit pattern contributes independently and universally to the entanglement entropy, leading to a characteristic volume-law scaling. Crucially, this universal contribution remains identical for both free and interacting models, enabling decomposition of the total entanglement into pattern-specific components. Numerical verification in fermionic and bosonic chains confirms this volume-law fragmentation phenomenon. For fermionic systems, we derive analytical expressions where many-body entanglement becomes expressible through few-body entanglement components. Notably, this analytical framework extends to spin-1/2 XXZ chains through appropriate identifications.

17 pages, 8 figures, published version

References in corpus (8)

• Entanglement of low-energy excitations in Conformal Field Theory
• Entanglement Entropy of Eigenstates of Quantum Chaotic Hamiltonians
• Global characteristics of all eigenstates of local many-body Hamiltonians: participation ratio and entanglement entropy
• Bound states and entanglement in the excited states of quantum spin chains
• Shell-Filling Effect in the Entanglement Entropies of Spinful Fermions
• Position momentum Duality in the Entanglement Spectrum of Free Fermions
• Comb entanglement in quantum spin chains
• Entanglement Entropies of the quarter filled Hubbard model