Approximation schemes for the study of multi‐band Gutzwiller wave functions. Issue 1 (8th August 2016)

• Record Type: Journal Article
• Authors: Bünemann, Jörg; Linneweber, Thorben; Gebhard, Florian
• Is Part Of: Physica status solidi. Volume 254:Issue 1(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-08-08
• Subjects: Gutzwiller wave functions -- Multi‐band Hubbard models -- superconductivity; Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201600166
• Languages: English
• ISSNs: 0370-1972

Abstract

Abstract: The minimum of the Gutzwiller energy functional depends on the number of parameters considered in the variational state. For a three‐orbital Hubbard model, we find that the frequently used diagonal Ansatz is very accurate in high‐symmetry situations. For lower symmetry, induced by a crystal‐field splitting or the spin–orbit coupling, the discrepancies in energy between the most general and a diagonal Gutzwiller Ansatz can be quite significant. We discuss approximate schemes that may be employed in multi‐band cases where a minimization of the general Gutzwiller energy functional is too demanding numerically.