Volume 80, Number 5, December 2007
Article Number 50007
Number of page(s) 6
Section General
Published online 31 October 2007
EPL, 80 (2007) 50007
DOI: 10.1209/0295-5075/80/50007

Non-perturbative renormalization group approach to zero-temperature Bose systems

N. Dupuis1, 2, 3 and K. Sengupta4

1  Laboratoire de Physique Théorique de la Matière Condensée, CNRS - UMR 7600, Université Pierre et Marie Curie 4 Place Jussieu, 75252 Paris Cedex 05, France
2  Laboratoire de Physique des Solides, CNRS - UMR 8502, Université Paris-Sud - 91405 Orsay, France
3  Department of Mathematics, Imperial College - 180 Queen's Gate, London SW7 2AZ, UK
4  TCMP Division, Saha Institute of Nuclear Physics - 1/AF Bidhannagar, Kolkata-700064, India

received 4 September 2007; accepted in final form 8 October 2007; published December 2007
published online 31 October 2007

We use a non-perturbative renormalization group technique to study interacting bosons at zero temperature. Our approach reveals the instability of the Bogoliubov fixed point when d$\leq$3 and yields the exact infrared behavior in all dimensions d > 1 within a rather simple theoretical framework. It also enables to compute the low-energy properties in terms of the parameters of a microscopic model. In one dimension and for not too strong interactions, it yields a good picture of the Luttinger-liquid behavior of the superfluid phase.

05.30.Jp - Boson systems.
03.75.Hh - Static properties of condensates; thermodynamical, statistical, and structural properties.
05.10.Cc - Renormalization group methods.

© Europhysics Letters Association 2007