Low-Energy Properties of a One-dimensional System of Interacting Bosons with Boundaries
Miguel A. Cazalilla
Abstract
PACS. 05.30.-d – Quantum statistical mechanics. PACS. 67.40.Db – Quantum statistical theory, ground state, elementary excitations. PACS. 05.30.Jp – Boson systems. Abstract. – The ground state properties and low-lying excitations of a (quasi) one-dimensional system of longitudinally confined interacting bosons are studied. This is achieved by extending Haldane’s harmonic-fluid description to open boundary conditions. The boson density, oneparticle density matrix, and momentum distribution are obtained accounting for finite-size and boundary effects. Friedel oscillations are found in the density. Finite-size scaling of the momentum distribution at zero momentum is proposed as a method to obtain from the experiment the exponent that governs phase correlations. The strong correlations between bosons induced by reduced dimensionality and interactions are displayed by a Bijl-Jastrow wave function for the ground state, which is also derived. The names of Tomonaga and Luttinger are commonly associated with interacting electron systems in one-dimension (1d). The so-called Tomonaga-Luttinger liquids (TLL’s) have the remarkable property that their low-energy spectrum is completely exhausted by gapless