New Functional Integral Approach to Strongly Correlated Fermi Systems: The Gutzwiller Approximation as a Saddle Point

作者：Gabriel Kotliar, Andrei E. Ruckenstein · 发表于：Physical Review Letters · 年份：1986 · DOI：10.1103/physrevlett.57.1362 · 被引用次数：1079 · 研究领域：Physics of Superconductivity and Magnetism、Quantum and electron transport phenomena、Cold Atom Physics and Bose-Einstein Condensates

We propose a new functional integral representation of the Hubbarda and Anderson models of lattice fermions. The simplest saddle-point approximation leads, at zero temperature, to the results derived from the Gutzwiller variational wave function. This approach uncovers the limitations of the Gutzwiller approximation and clarifies its connection to the "auxiliary-boson" mean-field theory of the Anderson model. This formulation leads to a novel strong-coupling mean-field theory which allows for a unified treatment of antiferromagnetism and ferromagnetism, metal-to-insulator transition, and Kondo compensation effects.