title: Enhancing the detection of natural thermal entanglement with disorder.
abstract: Physical systems have some degree of disorder present in them. We discuss how to treat natural, thermal entanglement in any random macroscopic system from which a thermodynamic witness bounded by a constant can be found. We propose that functional many-body perturbation theory be applied to allow either a quenched or an annealed average over the disorder to be taken. We find, when considering the example of an XX Heisenberg spin chain with a random coupling strength, that the region of natural entanglement detected by both witnesses can be enhanced by the disorder.
authors.affiliation: Department of Physics and Astronomy, EC Stoner Building, University of Leeds, Leeds, LS2 9JT, United Kingdom.
authors.forename: Jenny
authors.initials: J
authors.lastname: Hide
authors.forename: Wonmin
authors.initials: W
authors.lastname: Son
authors.forename: Vlatko
authors.initials: V
authors.lastname: Vedral