Superfluidity within Exact Renormalisation Group approach
arXiv:nucl-th/0512083 · doi:10.1088/0305-4470/39/25/S19
Abstract
The application of the exact renormalisation group to a many-fermion system with a short-range attractive force is studied. We assume a simple ansatz for the effective action with effective bosons, describing pairing effects and derive a set of approximate flow equations for the effective coupling including boson and fermionic fluctuations. The phase transition to a phase with broken symmetry is found at a critical value of the running scale. The mean-field results are recovered if boson-loop effects are omitted. The calculations with two different forms of the regulator was shown to lead to similar results.
17 pages, 3 figures, to appear in the proceedings of Renormalization Group 2005 (RG 2005), Helsinki, Finland, 30 Aug - 3 Sep 2005