Approximation schemes for the study of multi-band Gutzwiller wave functions

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• 作者：Jö ; rg Bü ; nemann ; Thorben Linneweber and Florian Gebhard
• 刊名：physica status solidi (b)
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：254
• 期：1
• 全文大小：829K
• ISSN：1521-3951

文摘

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.