Low-energy excitations of a one-dimensional Bose gas with weak contact repulsion

Abstract

We study elementary excitations of a system of one-dimensional bosons with weak contact repulsion. We show that the Gross-Pitaevskii regime, in which the excitations are the well-known Bogoliubov quasiparticles and dark solitons, does not extend to the low energy limit. Instead, the spectra of both excitations have finite curvatures at zero momentum, in agreement with the phenomenological picture of fermionic quasiparticles. We describe analytically the crossover between the Gross-Pitaevskii and the low-energy regimes, and discuss implications of our results for the behavior of the dynamic structure factor.

References in corpus (5)

• Many-Body Physics with Ultracold Gases
• Dynamic response of one-dimensional interacting fermions
• The dynamical spin structure factor for the anisotropic spin-1/2 Heisenberg chain
• Phenomenology of One-Dimensional Quantum Liquids Beyond the Low-Energy Limit
• Fermionic Quasiparticle Representation of Tomonaga-Luttinger Hamiltonian

Cited by in corpus (7)

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• The density of a one-dimensional Bose gas far from an impurity
• Local Properties of the Rapidity Distribution in the Lieb-Liniger Model
• Love--Lieb integral equations: applications, theory, approximations, and computation