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Integrability of the Russian doll BCS model

Dunning, Clare, Links, Jon (2004) Integrability of the Russian doll BCS model. Nuclear Physics B, 702 (3). pp. 481-494. ISSN 0550-3213. (doi:10.1016/j.nuclphysb.2004.09.021) (KAR id:4710)


We show that integrability of the BCS model extends beyond Richardson's model (where all Cooper pair scatterings have equal coupling) to that of the Russian doll BCS model for which the couplings have a particular phase dependence that breaks time-reversal symmetry. This model is shown to be integrable using the quantum inverse scattering method, and the exact solution is obtained by means of the algebraic Bethe ansatz. The inverse problem of expressing local operators in terms of the global operators of the monodromy matrix is solved. This result is used to find a determinant formulation of a correlation function for fluctuations in the Cooper pair occupation numbers. These results are used to undertake exact numerical analysis for small systems at half-filling.

Item Type: Article
DOI/Identification number: 10.1016/j.nuclphysb.2004.09.021
Uncontrolled keywords: BCS model cooper pair integrability algebraic Bethe ansatz
Subjects: Q Science > QA Mathematics (inc Computing science)
Divisions: Divisions > Division of Computing, Engineering and Mathematical Sciences > School of Mathematics, Statistics and Actuarial Science
Depositing User: Clare Dunning
Date Deposited: 08 Sep 2008 14:11 UTC
Last Modified: 16 Nov 2021 09:43 UTC
Resource URI: (The current URI for this page, for reference purposes)

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