A method to include the spin-fluctuation in the ab-initio electronic-structure calculation

TL;DR

This paper introduces a new ab-initio method that self-consistently incorporates spin-fluctuations into electronic-structure calculations, improving the accuracy of magnetic susceptibility predictions for transition metals.

Contribution

The paper presents a novel self-consistent approach to include spin-fluctuations in ab-initio calculations based on the Luttinger-Ward functional, extending previous theories.

Findings

Good agreement with experimental susceptibilities for Pd, Ni, Fe, and Co.

Method effectively captures temperature-dependent spin-fluctuation effects.

Enhances accuracy of magnetic property predictions in ab-initio calculations.

Abstract

We present a new method of ab-initio electronic-structure calculation including the spin-fluctuation (SF) self-consistently. We start from the Luttinger-Ward functional given as the sum of the LDA functional plus the temperature-dependent part of the SF energy functional. The size of interactions used in it are determined in a similar manner to the self-consistent renormalization theory by Moriya and Kawabata. Obtained paramagnetic susceptibilities on Pd, Ni, Fe, and fcc-Co above $T_c$ show rather good agreements with experiments.