Uncovering the mechanism of the impurity-selective Mott transition in paramagnetic V${}_2$O${}_3$

Abstract

While the phase diagrams of the one- and multi-orbital Hubbard model have been well studied, the physics of real Mott insulators is often much richer, material dependent, and poorly understood. In the prototype Mott insulator V${}_2$O${}_3$, chemical pressure was initially believed to explain why the paramagnetic-metal to antiferromagnetic-insulator transition temperature is lowered by Ti doping while Cr doping strengthens correlations, eventually rendering the high-temperature phase paramagnetic insulating. However, this scenario has been recently shown both experimentally and theoretically to be untenable. Based on full structural optimization, we demonstrate via the charge self-consistent combination of density functional theory and dynamical mean-field theory that changes in the V${}_2$O${}_3$ phase diagram are driven by defect-induced local symmetry breakings resulting from dramatically different couplings of Cr and Ti dopants to the host system. This finding emphasizes the high sensitivity of the Mott metal-insulator transition to the local environment and the importance of accurately accounting for the one-electron Hamiltonian, since correlations crucially respond to it.

5 pages, 5 figures, supplementary information

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• How chromium doping affects the correlated electronic structure of V2O3
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Cited by in corpus (13)

• The role of defects in the metal-insulator transition in VO${}_2$ and V${}_2$O${}_3$
• The magnetic origin of the metal-insulator transition in V2O3: Mott meets Slater
• Interplay of charge-transfer and Mott-Hubbard physics approached by an efficient combination of self-interaction correction and dynamical mean-field theory
• Two-Particle Self-Consistent method for the multi-orbital Hubbard model
• Frustrated Magnetism in Mott Insulating (V${}_{1-x}$Cr${}_x$)${}_2$O${}_3$
• Imaging the itinerant-to-localized transmutation of electrons across the metal-to-insulator transition in V${}_2$O${}_3$
• Unusual Mott transition associated with charge-order melting in BiNiO${}_3$ under pressure
• Impact of biaxial and uniaxial strain on V${}_2$O${}_3$
• Metal-insulator transition and local-moment collapse in negative charge-transfer CaFeO${}_3$ under pressure
• Sign-Free Determinant Quantum Monte Carlo Study of Excitonic Density Orders in a Two-Orbital Hubbard-Kanamori Model
• Synthesis of V${}_2$O${}_3$ Nanoplates
• Spatial inhomogeneity and the metal-insulator transition in Ca${}_3$(Ru${}_{1-x}$Ti${}_x$)${}_2$O${}_7$
• Role of surface termination in the metal-insulator transition of V${}_2$O${}_3$(0001) ultrathin films