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Sr$_2$(Ba$_2$)VO$_4$ under pressure -- an orbital switch and potential $d^1$ superconductor

R. Arita·A. Yamasaki·K. Held·J. Matsuno·K. Kuroki
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Abstract

We study Sr$_2$(Ba$_2$)VO$_4$ under high pressure by means of the local density approximation + dynamical mean field theory method. While Sr$_2$VO$_4$ is a 1/6-filling three-band system at ambient pressure with a small level splitting between the $d_{xy}$- and $d_{yz/zx}$-bands, we show that an orbital polarization occurs under uniaxial pressure, resulting in dramatic changes of the magnetic, optical, and transport properties. When pressure is applied in the $c$-direction, a $d^1$ analog of $d^9$ cuprates is realized, making Sr$_2$(Ba$_2$)VO$_4$ a possible candidate for a $d^1$ superconductor. Experimentally, this uniaxial pressure can be realized by growing Ba$_2$VO$_4$ on a substrate with lattice constant 4.1-4.2 Å.

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R. Arita, A. Yamasaki, K. Held, J. Matsuno, K. Kuroki. 2006-11-28. Sr$_2$(Ba$_2$)VO$_4$ under pressure -- an orbital switch and potential $d^1$ superconductor. https://doi.org/10.1103/physrevb.75.174521

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