Compact approximate solution to the Friedel-Anderson impurity problem
نویسنده
چکیده
An approximate ground state of the Anderson-Friedel impurity problem is presented in a very compact form. It requires solely the optimization of two localized electron states and consists of four Slater states Slater determinants . The resulting singlet ground-state energy lies far below the Anderson mean-field solution and agrees well with the numerical results by Gunnarsson and Schönhammer, who used an extensive 1/Nf expansion for a spin2 impurity with double occupancy of the impurity level.
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