Year: 2012
Type: article
Abstract: A quantum model can be mapped to a classical model in one higher dimension. Here we introduce a finite-temperature correlation measure based on a reduced density matrix obtained by cutting the classical system along the imaginary time (inverse temperature) axis. We show that the von Neumann entropy of shares many properties with the mutual information, yet is based on a simpler geometry and is thus easier to calculate. For one-dimensional quantum systems in the thermodynamic limit we prove that is non-extensive for all temperatures T . For the integrable transverse Ising and XXZ models we demonstrate that the entanglement spectra of in the limit T → 0 are described by free-fermion Hamiltonians and reduce to those of the regular reduced density matrix ρ A —obtained by a spatial instead of an imaginary time cut—up to degeneracies.
Author: Jesko Sirker
Institution: University of Kaiserslautern
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W2168069762