Many-polaron description of impurities in a Bose-Einstein condensate in the weak-coupling regime

Journal Article · Thu Dec 15 04:00:00 EST 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.063612· OSTI ID:22095663

Casteels, W.; Devreese, J. T. ^[1]; Tempere, J. ^[1]

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1. TQC, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium)

The weak-coupling many-polaron formalism is applied to the case of the polaronic system consisting of impurities in a Bose-Einstein condensate. This allows investigating the ground-state properties and the response of the system to Bragg spectroscopy. Then, this theory is applied to the system of spin-polarized fermionic lithium-6 impurities in a sodium condensate. The Bragg spectrum reveals a peak that corresponds to the emission of Bogoliubov excitations. Both the ground-state properties and the response spectrum show that the polaronic effect vanishes at high densities. We also look at two possibilities to define the polaronic effective mass and observe that this results in a different quantitative behavior if multiple impurities are involved.

• OSTI ID: 22095663
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 84; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BOSE-EINSTEIN CONDENSATION
COUPLING
DENSITY
EFFECTIVE MASS
EXCITATION
FERMIONS
GROUND STATES
LITHIUM 6
POLARONS
SODIUM
SPECTROSCOPY
SPIN ORIENTATION