Entanglement Hamiltonian in the non-Hermitian SSH model

Abstract

Entanglement Hamiltonians provide the most comprehensive characterisation of entanglement in extended quantum systems. A key result in unitary quantum field theories is the Bisognano-Wichmann theorem, which establishes the locality of the entanglement Hamiltonian. In this work, our focus is on the non-Hermitian Su-Schrieffer-Heeger (SSH) chain. We study the entanglement Hamiltonian both in a gapped phase and at criticality. In the gapped phase we find that the lattice entanglement Hamiltonian is compatible with a lattice Bisognano-Wichmann result, with an entanglement temperature linear in the lattice index. At the critical point, we identify a new imaginary chemical potential term absent in unitary models. This operator is responsible for the negative entanglement entropy observed in the non-Hermitian SSH chain at criticality.

21 pages, 8 figures

References in corpus (12)

• Entanglement Spectrum as a Generalization of Entanglement Entropy: Identification of Topological Order in Non-Abelian Fractional Quantum Hall Effect States
• Towards a derivation of holographic entanglement entropy
• Topological phases in the non-Hermitian Su-Schrieffer-Heeger model
• Entanglement spectrum in one-dimensional systems
• Entanglement hamiltonians in two-dimensional conformal field theory
• Mean-field dynamics of a non-Hermitian Bose-Hubbard dimer
• Local temperatures and local terms in modular Hamiltonians
• Entanglement spectrum degeneracy and Cardy formula in 1+1 dimensional conformal field theories
• Symmetry-resolved entanglement in critical non-Hermitian systems
• On the continuum limit of the entanglement Hamiltonian
• Lattice Bisognano-Wichmann modular Hamiltonian in critical quantum spin chains
• Entanglement Hamiltonian of a nonrelativistic Fermi gas

Cited by in corpus (11)

• Quantum entanglement and non-Hermiticity in free-fermion systems
• Entanglement Hamiltonians and the quasiparticle picture
• Dynamics of monitored SSH Model in Krylov Space: From Complexity to Quantum Fisher Information
• Thermodynamics and entanglement entropy of the non-Hermitian SSH model
• Entanglement Hamiltonian and effective temperature of non-Hermitian quantum spin ladders
• Phase transitions in a non-Hermitian Su-Schrieffer-Heeger model via Krylov spread complexity
• Complex entanglement entropy for complex conformal field theory
• On the Bisognano-Wichmann entanglement Hamiltonian of nonrelativistic fermions
• Topologically protected negative entanglement
• Supercharging exceptional points: Full-spectrum pairwise coalescence in non-Hermitian systems
• Non-Hermiticity induced thermal entanglement phase transition