Volume 87, Number 2, July 2009
Article Number 27010
Number of page(s) 5
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 18 August 2009
EPL, 87 (2009) 27010
DOI: 10.1209/0295-5075/87/27010

Correlations in a two-dimensional Bose gas with long-range interaction

B. Laikhtman and R. Rapaport

Racah Institute of Physics, Hebrew University - Jerusalem 91904, Israel

received 11 May 2009; accepted in final form 15 July 2009; published July 2009
published online 18 August 2009

We study the correlations of two-dimensional dipolar bosons with excitons in semiconductor bilayers as a specific case, in the whole temperature-concentration region. We show that at low concentrations, the Bose degeneracy is accompanied by strong multi-particle correlations and the system behaves as a Bose liquid. At high concentrations the repulsion suppresses quantum coherence and the system behaves as a classical liquid down to a temperature lower than typical for a Bose gas. The interaction energy of the particles is a sensitive tool for a measurement of the correlations. This theory can apply to other systems of bosons with extended interaction.

71.35.Lk - Collective effects (Bose effects, phase space filling, and excitonic phase transitions).
05.30.Jp - Boson systems.
73.20.Mf - Collective excitations (including excitons, polarons, plasmons and other charge-density excitations).

© EPLA 2009