Modeling of complex oxide materials from the first principles: systematic applications to vanadates RVO3 with distorted perovskite structure

Abstract

"Realistic modeling" is a new direction of electronic structure calculations, where the main emphasis is made on the construction of some effective low-energy model entirely within a first-principle framework. Ideally, it is a model in form, but with all the parameters derived rigorously, on the basis of first-principles electronic structure calculations. The method is especially suit for transition-metal oxides and other strongly correlated systems, whose electronic and magnetic properties are predetermined by the behavior of some limited number of states located near the Fermi level. After reviewing general ideas of realistic modeling, we will illustrate abilities of this approach on the wide series of vanadates RVO3 (R= La, Ce, Pr, Nd, Sm, Gd, Tb, Yb, and Y) with distorted perovskite structure. Particular attention will be paid to computational tools, which can be used for microscopic analysis of different spin and orbital states in the partially filled t2g-band. We will explicitly show how the lifting of the orbital degeneracy by the monoclinic distortion stabilizes C-type antiferromagnetic (AFM) state, which can be further transformed to the G-type AFM state by changing the crystal distortion from monoclinic to orthorhombic one. Two microscopic mechanisms of such a stabilization, associated with the one-electron crystal field and electron correlation interactions, are discussed. The flexibility of the orbital degrees of freedom is analyzed in terms of the magnetic-state dependence of interatomic magnetic interactions.

23 pages, 13 figures

References in corpus (7)

• Screened Coulomb interaction in the maximally localized Wannier basis
• Combining DFT and Many-Body Methods to Understand Correlated Materials
• Lattice Distortion and Magnetism of 3d-$t_{2g}$ Perovskite Oxides
• Electronic Structure of Strongly Correlated Systems Emerging from Combining Path-Integral Renormalization Group with Density Functional Approach
• Construction of Wannier functions from localized atomic-like orbitals
• Dynamics of spin and orbital phase transitions in YVO3
• Correlation Energies in Distorted 3d-$t_{2g}$ Perovskite Oxides