title: Particles, holes, and solitons: a matrix product state approach.
abstract: We introduce a variational method for calculating dispersion relations of translation invariant (1+1)-dimensional quantum field theories. The method is based on continuous matrix product states and can be implemented efficiently. We study the critical Lieb-Liniger model as a benchmark and excellent agreement with the exact solution is found. Additionally, we observe solitonic signatures of Lieb's type II excitation. In addition, a nonintegrable model is introduced where a U(1)-symmetry breaking term is added to the Lieb-Liniger Hamiltonian. For this model we find evidence of a nontrivial bound-state excitation in the dispersion relation.
authors.affiliation: Vienna Center for Quantum Science, Universität Wien, Boltzmanngasse 5, A-1090 Wien, Austria.
authors.forename: Damian
authors.initials: D
authors.lastname: Draxler
authors.forename: Jutho
authors.initials: J
authors.lastname: Haegeman
authors.forename: Tobias J
authors.initials: TJ
authors.lastname: Osborne
authors.forename: Vid
authors.initials: V
authors.lastname: Stojevic
authors.forename: Laurens
authors.initials: L
authors.lastname: Vanderstraeten
authors.forename: Frank
authors.initials: F
authors.lastname: Verstraete