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Orbital Switching and the First-Order Insulator-Metal Transition in Paramagnetic V_2O_3

M. S. Laad·L. Craco·E. Müller-Hartmann
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Abstract

The first-order metal-insulator transition (MIT) in paramagnetic $V_{2}O_{3}$ is studied within the ab-initio scheme LDA+DMFT, which merges the local density approximation (LDA) with dynamical mean field theory (DMFT). With a fixed value of the Coulomb $U=6.0 eV$, we show how the abrupt pressure driven MIT is understood in a new picture: pressure-induced decrease of the trigonal distortion within the strong correlation scenario (which is not obtained within LDA). We find good quantitative agreement with $(i)$ switch of the orbital occupation of $(a_{1g},e_{g1}^π, e_{g2}^π)$ and the spin state S=1 across the MIT, $(ii)$ thermodynamics and $dc$ resistivity, and $(iii)$ the one-electron spectral function, within this new scenario.

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M. S. Laad, L. Craco, E. Müller-Hartmann. 2002-11-11. Orbital Switching and the First-Order Insulator-Metal Transition in Paramagnetic V_2O_3. https://doi.org/10.1103/physrevlett.91.156402

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