Momentum distribution of a freely expanding Lieb-Liniger gas

Scientific paper - Original scientific paper

• Author: Dario Jukić
• Author: Bruno Klajn
• Author: Hrvoje Buljan
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

We numerically study free expansion of a few Lieb-Liniger bosons, which are initially in the ground state of an infinitely deep hard-wall trap. Numerical calculation is carried out by employing a standard Fourier transform, as follows from the Fermi-Bose transformation for a time-dependent Lieb-Liniger gas. We study the evolution of the momentum distribution, the real-space single-particle density, and the occupancies of natural orbitals. Our numerical calculation allows us to explore the behavior of these observables in the transient regime of the expansion, where they are nontrivially affected by the particle interactions. We derive analytically (by using the stationary phase approximation) the formula which connects the asymptotic shape of the momentum distribution and the initial state. For sufficiently large times, the momentum distribution coincides (up to a simple scaling transformation) with the shape of the real-space single-particle density (the expansion is asymptotically ballistic). Our analytical and numerical results are in good agreement.

• Keywords (english): nonequilibrium dynamics; bosons; interactions
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review A
• Numbering: vol. 79, no. 3, 033612
• p-ISSN: 1050-2947
• DOI: https://doi.org/10.1103/PhysRevA.79.033612
• URN:NBN: urn:nbn:hr:217:789658
• Publication: 2009
• Project: Number: 119-0000000-1015; Title (croatian): Nelinearne pojave i valna dinamika u fotoničkim sustavima; Leader: Hrvoje Buljan; Jurisdiction: Croatia; Funding stream: ZP
• Document URL: http://link.aps.org/doi/10.1103/PhysRevA.79.033612
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2009) by the American Physical Society. Received 26 January 2009; published 12 March 2009.
• Created on: 2019-10-19 19:58:56