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Interpolative Approach for Solving Quantum Impurity Model Based on the Slave--Boson Mean--Field Approximation

V. Oudovenko·K. Haule·S. Y. Savrasov·D. Villani·G. Kotliar
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Abstract

A rational representation for the self-energy is explored to interpolate the solution of the Anderson impurity model in general orbitally degenerate case. Several constrains such as the Friedel's sum rule, high--frequency moments and the value of quasiparticle residue are used to establish the equations for the coefficients of the interpolation. We test two fast techniques, the slave--boson mean--field and the Hubbard I approximation to determine the coefficients. The obtained self--energies are compared with the results of numerically exact Quantum Monte Carlo method. We find that using the slave--boson mean--field approach we can construct an accurate self--energy for all frequencies via the proposed interpolation procedure.

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V. Oudovenko, K. Haule, S. Y. Savrasov, D. Villani, G. Kotliar. 2004-01-27. Interpolative Approach for Solving Quantum Impurity Model Based on the Slave--Boson Mean--Field Approximation. https://arxiv.org/abs/cond-mat/0401539

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