First-Principles Computation of YVO3; Combining Path-Integral Renormalization Group with Density-Functional Approach

TL;DR

This paper combines density-functional theory with the path-integral renormalization group to accurately compute the electronic structure and ground state properties of YVO3, a transition-metal oxide, improving previous estimates of its charge gap.

Contribution

It introduces a hybrid computational scheme that integrates DFT and PIRG to analyze complex correlated materials like YVO3.

Findings

Ground state exhibits G-type spin and C-type orbital orderings.

Charge gap estimated at approximately 0.7 eV, aligning with experimental data.

Method provides more accurate electronic structure predictions than conventional approaches.

Abstract

We investigate the electronic structure of the transition-metal oxide YVO3 by a hybrid first-principles scheme. The density-functional theory with the local-density-approximation by using the local muffin-tin orbital basis is applied to derive the whole band structure. The electron degrees of freedom far from the Fermi level are eliminated by a downfolding procedure leaving only the V 3d t2g Wannier band as the low-energy degrees of freedom, for which a low-energy effective model is constructed. This low-energy effective Hamiltonian is solved exactly by the path-integral renormalization group method. It is shown that the ground state has the G-type spin and the C-type orbital ordering in agreement with experimental indications. The indirect charge gap is estimated to be around 0.7 eV, which prominently improves the previous estimates by other conventional methods.