Tuning a Strain-Induced Orbital Selective Mott Transition in Epitaxial VO${}_2$

Abstract

We present evidence of strain-induced modulation of electron correlation effects and increased orbital anisotropy in the rutile phase of epitaxial VO${}_2$/TiO${}_2$ films from hard x-ray photoelectron spectroscopy and soft V L-edge x-ray absorption spectroscopy, respectively. By using the U(1) slave spin formalism, we further argue that the observed anisotropic correlation effects can be understood by a model of orbital selective Mott transition at a filling that is non-integer, but close to the half-filling. Because the overlaps of wave functions between $d$ orbitals are modified by the strain, orbitally-dependent renormalizations of the bandwidths and the crystal fields occur with the application of strain. These renormalizations generally result in different occupation numbers in different orbitals. We find that if the system has a non-integer filling number near the half-filling such as for VO${}_2$, certain orbitals could reach an occupation number closer to half-filling under the strain, resulting in a strong reduction in the quasiparticle weight $Z_{\alpha }$ of that orbital. Moreover, an orbital selective Mott transition, defined as the case with $Z_{\alpha }=0$ in some, but not all orbitals, could be accessed by epitaxial strain-engineering of correlated electron systems.

arXiv comment7 pages, 6 figures. First two authors contribute equally

References in corpus (18)

• Dynamical singlets and correlation-assisted Peierls transition in VO2
• Orbital-assisted metal-insulator transition in VO${}_2$
• Selective Mottness as a key to iron superconductors
• Orbital-selective Mott transitions in the degenerate Hubbard model
• Orbital-Selective Mott transition out of band degeneracy lifting
• Orbital selective Mott transition in multi-band systems: slave-spin representation and dynamical mean-field theory
• Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in A${}_x$Fe${}_{2-y}$Se${}_2$ (A=K, Rb) Superconductors
• Hund's coupling key role in multi-orbital correlations
• Vanadium dioxide : A Peierls-Mott insulator stable against disorder
• Effects of strain on the electronic structure of VO_2
• Orbital Dependent Phase Control in Ca2-xSrxRuO4
• U(1) Slave-spin theory and its application to Mott transition in a multi-orbital model for iron pnictides
• Single Mott Transition in Multi-Orbital Hubbard Model
• Slave spin cluster mean field theory away from half-filling: Application to the Hubbard and the extended Hubbard Model
• Mott Transition in Multi-Orbital Models for Iron Pnictides
• Exotic magnetic order in the orbital-selective Mott regime of multiorbital systems
• Photoemission evidence for crossover from Peierls-like to Mott-like transition in highly strained VO${}_2$
• La${}_2$O${}_3$Fe${}_2$Se${}_2$, a Mott insulator on the brink of orbital-selective metalization

Cited by in corpus (12)

• Non-Thermal Emergence of an Orbital-Selective Mott Phase in FeTe${}_{1-x}$Se${}_x$
• Correlation-Driven Electronic Reconstruction in FeTe${}_{1-x}$Se${}_x$
• Orbital-selective Mott phase in multiorbital models for iron pnictides and chalcogenides
• Massively strained VO2 thin film growth on RuO2
• Cooperative Effects of Strain and Electron Correlation in Epitaxial VO2 and NbO2
• Electron Correlation driven Metal-Insulator transition in Strained and Disordered VO2 films
• Persistent flat band splitting and strong selective band renormalization in a kagome magnet thin film
• Correlation induced emergent charge order in metallic vanadium dioxide
• Occupation switching of $d$ orbitals probed via hyperfine interactions in vanadium dioxide
• Revisit of Antiferromagnetism in Hubbard Model by A Cluster Slave-Spin Method
• Mechanism of the Resistivity Switching Induced by the Joule Heating in Crystalline NbO${}_2$
• Single-component molecular material hosting antiferromagnetic and spin-gapped Mott subsystems