Collective excitation frequencies of bosons in a parabolic potential with interparticle harmonic interactions

Citation
A. Minguzzi et al., Collective excitation frequencies of bosons in a parabolic potential with interparticle harmonic interactions, PHYS LETT A, 267(5-6), 2000, pp. 416-419
Citations number
9
Categorie Soggetti
Physics
Journal title
PHYSICS LETTERS A
ISSN journal
03759601 → ACNP
Volume
267
Issue
5-6
Year of publication
2000
Pages
416 - 419
Database
ISI
SICI code
0375-9601(20000327)267:5-6<416:CEFOBI>2.0.ZU;2-S
Abstract
The fact that the ground-state first-order density matrix for bosons in a p arabolic potential with interparticle harmonic interactions is known in exa ct form is here exploited to study collective excitations in the weak-coupl ing regime. Oscillations about the ground-state density are treated analyti cally by a linearized equation of motion which includes a kinetic energy co ntribution. We show that the dipole mode has the frequency of the bare trap , in accord with the Kohn theorem, and derive explicit expressions for the frequencies of the higher-multipole modes in terms of a frequency renormali zed by the interactions. (C) 2000 Elsevier Science B.V. All rights reserved .