We consider the problems of calculating the dynamical order parameter two-point function at finite temperatures and the one-point function after a quantum quench in the transverse field Ising chain. Both of these can be expressed in terms of form factor sums in the basis of physical excitations of the model. We develop a general framework for carrying out these sums based on a decomposition of form factors into partial fractions, which leads to a factorization of the multiple sums and permits them to be evaluated asymptotically. This naturally leads to systematic low density expansions. At late times these expansions can be summed to all orders by means of a determinant representation. Our method has a natural generalization to semi-local operators in interacting integrable models.
Cited by 1
Isabelle Bouchoule et al., The effect of atom losses on the distribution of rapidities in the one-dimensional Bose gas
SciPost Phys. 9, 044 (2020) [Crossref]
Ontology / TopicsSee full Ontology or Topics database.
Authors / Affiliations: mappings to Contributors and OrganizationsSee all Organizations.
- 1 Rudolf Peierls Centre for Theoretical Physics, University of Oxford
- 2 Laboratoire de Physique Théorique et Modèles Statistiques [LPTMS]