Quantum embedding description of the Anderson lattice model with the ghost Gutzwiller approximation

• Published in: Physical review. B 2021-08, Vol.104 (8), p.1, Article L081103
• Main Authors: Frank, Marius S., Lee, Tsung-Han, Bhattacharyya, Gargee, Tsang, Pak Ki Henry, Quito, Victor L., Dobrosavljević, Vladimir, Christiansen, Ove, Lanatà, Nicola
• Format: Article
• Language: English
• Subjects: Approximation; Insulators; Mean field theory; Metal-insulator transition; Phase diagrams
• ISSN: 2469-9950; 2469-9969; 2469-9969
• DOI: 10.1103/PhysRevB.104.L081103

We present benchmark calculations of the Anderson lattice model based on the recently developed "ghost Gutzwiller approximation". Our analysis shows that, in some parameters regimes, the predictions of the standard Gutzwiller approximation can be incorrect by orders of magnitude for this model. We show that this is caused by the inability of this method to describe simultaneously the Mott physics and the hybridization between correlated and itinerant degrees of freedom-whose interplay often governs the metal-insulator transition in real materials. Finally, we show that the ghost Gutzwiller approximation solves this problem, providing us with results in remarkable agreement with dynamical mean-field theory throughout the entire phase diagram, while being much less computationally demanding. We provide an analytical explanation of these findings and discuss their implications within the context of ab-initio computation of strongly correlated matter.