2005/06/30 by Bernhard Edegger, Noboru Fukushima, Claudius Gros +1
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Theoretical and Computational Physics #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.72.134504
published as Phys. Rev. B 72, 134504 (2005) · 10 pages, 5 figures
openalex publication_date 2005/10/05 · arxiv created 2005/12/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The effects of the Gutzwiller projection on a BCS wave function with varying particle number are considered. We show that a fugacity factor has to be introduced in these wave functions when they are Gutzwiller projected, and derive an expression for this factor within the Gutzwiller approximation. We examine the effects of the projection operator on BCS wave functions by calculating the average number of particles before and after projection. We also calculate particle number fluctuations in a projected BCS state. Finally, we point out the differences between projecting BCS wave functions in the micro- and grand-canonical schemes, and discuss the relevance of our results for variational Monte Carlo studies.