Role of nonlocal exchange in the electronic structure of correlated oxides

Iori, Federico; Gatti, Matteo; Rubio, Ángel

doi:10.1103/physrevb.85.115129

Cited by 69 publications

(65 citation statements)

References 93 publications

(166 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Electronic structure calculations based on density functional theory (DFT) within the local density approximation (LDA) or the generalized gradient approximation (GGA) fail to reproduce the insulating nature of the M 1 phase. [4,21] More sophisticated methods such as the LDA+U [22], hybrid functionals [23][24][25], GW [26,27] or dynamical mean field theory (DMFT) [12,28,29] have been applied to this system. Interestingly, although these methods attempt to address different aspects of the electron-electron correlation, they are all able to predict an insulating gap develops in the M 1 phase.…”

Section: Fig 1 (Color Online) Structures Of Different Vo2 Phases (A)mentioning

confidence: 99%

VO2: Orbital competition, magnetism, and phase stability

et al. 2012

View full text Add to dashboard Cite

The relative phase stability of VO2 is one of the most fundamental issues concerning the metalinsulator transition in this material but has so far largely unexplored theoretically. We investigate the relative stability of various phases of VO2 using different levels of energy functionals within density functional theory (DFT). It is found that straightforward applications of several popular energy functionals, including the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional, result in a wrong prediction for the ground state of VO2. In particular, although the HSE and DFT+U methods are able to produce a band gap in the M1 phase, they strongly favor the formation of local magnetic moments, a result that clearly disagrees with experiments. We also examine the effect of the occupation and the redistribution of the d derived t2g (i.e., dxz, dyz and d x 2 −y 2 ) orbitals of V atoms on the calculated relative phase stability of VO2. We find that a small change in d-occupation can result in a drastically different theoretical prediction. With the introduction of an orbital-dependent potential, a complete separation between the d x 2 −y 2 derived valence band and dxz and dyz derived conduction bands in the M1 phase is achieved, resulting in a slight redistribution of the d occupation and a more faithful account of the polarization of the t2g orbitals. This slight rearrangement of the d occupation also leads to a relative phase stability of VO2 (including structural and magnetic phases) that agrees well with experiment.

show abstract

Section: Fig 1 (Color Online) Structures Of Different Vo2 Phases (A)mentioning

confidence: 99%

VO2: Orbital competition, magnetism, and phase stability

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Hybrid functionals have been used to calculate the single particle band structures of various transition metal oxides. [50][51][52][53][54] The HSE functional was used previously to study the MIT in VO 2 with changing the crystal structure, 50 but based on experimental atomic coordinates. Here, we find that the sX functional will reproduce the correct single-particle electronic structure in all the three phases of V 2 O 3 without any fitting parameter.…”

Section: Introductionmentioning

confidence: 99%

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

Guo

Clark

Robertson

2014

The Journal of Chemical Physics

View full text Add to dashboard Cite

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. The electronic structure of vanadium sesquioxide V 2 O 3 in its different phases has been calculated using the screened exchange hybrid density functional. The hybrid functional accurately reproduces the experimental electronic properties of all three phases, the paramagnetic metal (PM) phase, the anti-ferromagnetic insulating phase, and the Cr-doped paramagnetic insulating (PI) phase. We find that a fully relaxed supercell model of the Cr-doped PI phase based on the corundum structure has a monoclinic-like local strain around the substitutional Cr atoms. This is found to drive the PI-PM transition, consistent with a Peierls-Mott transition. The PI phase has a calculated band gap of 0.15 eV, in good agreement with experiment. © 2014 AIP Publishing LLC.

show abstract

“…This view had been reinforced by the failure of density functional theory (DFT), within the LDA approximation, to reproduce the insulating nature of the M 1 crystal structure without including a Hubbard-U term. However, very recent calculations have shown that, when non-local exchange interactions are accounted for, the insulating and metallic phases can be obtained within DFT and additional correlation effects are not required 4,5 . The discovery of a photoinduced IM transition in VO 2 has opened new avenues for investigating the transition process 6 .…”

mentioning

confidence: 99%

Tracking the evolution of electronic and structural properties of VO2during the ultrafast photoinduced insulator-metal transition

et al. 2013

View full text Add to dashboard Cite

We present a detailed study of the photoinduced insulator-metal transition in VO2 with broadband time-resolved reflection spectroscopy. This allows us to separate the response of the lattice vibrations from the electronic dynamics and observe their individual evolution. When exciting well above the photoinduced phase transition threshold, we find that the restoring forces that describe the ground state monoclinic structure are lost during the excitation process, suggesting that an ultrafast change in lattice potential drives the structural transition. However, by performing a series of pump-probe measurements during the non-equilibrium transition, we observe that the electronic properties of the material evolve on a different, slower, timescale. This separation of timescales suggests that the early state of VO2, immediately after photoexcitation, is a non-equilibrium state that is not well defined by either the insulating or metallic phase.

show abstract

Role of nonlocal exchange in the electronic structure of correlated oxides

Cited by 69 publications

References 93 publications

VO2: Orbital competition, magnetism, and phase stability

VO2: Orbital competition, magnetism, and phase stability

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

Tracking the evolution of electronic and structural properties of VO2during the ultrafast photoinduced insulator-metal transition

Contact Info

Product

Resources

About