Electronic structure of paramagneticV2O3: Strongly correlated metallic and Mott insulating phase

Abstract

LDA+DMFT, the computation scheme merging the local density approximation and the dynamical mean-field theory, is employed to calculate spectra both below and above the Fermi energy and spin and orbital occupations in the correlated paramagnetic metallic and Mott insulating phase of V 2 O 3 . The selfconsistent DMFT equations are solved by quantum Monte Carlo simulations. Room temperature calculations provide direct comparison with experiment. They show a significant increase of the quasiparticle height in comparison with the results at 1160 K. We also obtain new insights into the nature of the MottHubbard transition in V 2 O 3 . Namely, it is found to be strikingly different from that in the one-band Hubbard model due to the orbital degrees of freedom. Furthermore we resolve the puzzle of the unexpectedly small Mott gap in Cr-doped V 2 O 3 .

Magnetic collapse and the behavior of transition metal oxides at high pressure

“…In particular, this advanced theory makes it possible to determine the electronic structure and phase stability of paramagnetic correlated materials at finite temperatures, e.g., near a Mott insulator-metal transition [13][14][15][20][21][22][23][24][25][26][27][28]. The DFT+DMFT approach has been used to study the electronic and structural properties of correlated electron materials [11][12][13][14][15][16][17][18][19][20], including transition metal monoxides [22][23][24][25][26][27][28][29]. In practice, however, these calculations employed different approximations, resulting in various scenarios for the IMT.…”

“…This obstacle can be overcome by employing, e.g., a state-of-the-art method for calculating the electronic structure of strongly correlated materials [density functional plus dynamical mean-field theory (DFT+DMFT)] [9,10]. It merges ab initio band-structure techniques, such as the local density approximation (LDA) or the generalized gradient approximation (GGA), with dynamical mean-field theory (DMFT) of correlated electrons [9], providing a good quantitative description of the electronic and lattice properties [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. In particular, this advanced theory makes it possible to determine the electronic structure and phase stability of paramagnetic correlated materials at finite temperatures, e.g., near a Mott insulator-metal transition [13][14][15][20][21][22][23][24][25][26][27][28].…”

“…It merges ab initio band-structure techniques, such as the local density approximation (LDA) or the generalized gradient approximation (GGA), with dynamical mean-field theory (DMFT) of correlated electrons [9], providing a good quantitative description of the electronic and lattice properties [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. In particular, this advanced theory makes it possible to determine the electronic structure and phase stability of paramagnetic correlated materials at finite temperatures, e.g., near a Mott insulator-metal transition [13][14][15][20][21][22][23][24][25][26][27][28]. The DFT+DMFT approach has been used to study the electronic and structural properties of correlated electron materials [11][12][13][14][15][16][17][18][19][20], including transition metal monoxides [22][23][24][25...…”

Calculation of metallic and insulating phases of V2O3 by hybrid density functionals

“…[16][17][18][19][20][21][22][23][24][25][26] The simple local spin density approximation (LSDA) is known to be unable to give a band gap for the insulating phases of V 2 O 3 16 due to its inability to treat the localized d electrons correctly. On the other hand, the LSDA+U method can open up a gap for open-shell d electron systems, 17 but with the disadvantage that the on-site repulsion, U, is a variable.…”

Spin Freezing Transition and Non-Fermi-Liquid Self-Energy in a Three-Orbital Model

“…Multiorbital models have been studied in Refs. [4,5,6,7,8,9,10]. New physics related to the appearance of magnetic moments has been considered in the context of the orbitally selective Mott transition which may occur if the orbital degeneracy is lifted [11,12,13,14,15], but for orbitally degenerate models it seems accepted that the essential concepts of a paramagnetic metal to paramagnetic insulator transition and a strongly correlated paramagnetic metal phase can be carried over from studies of the oneband situation.…”