<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>Sr</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:msub><mml:mrow><mml:mi>MoO</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>Sr</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi>RuO</mml:mi></mml:mrow><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>: Disentangling the Roles of Hund’s and van Hove Physics
Jonathan Karp, Max Bramberger, M. Grundner, Ulrich Schollwöck, Andrew J. Millis, Manuel Zingl
Abstract
${\mathrm{Sr}}_{2}{\mathrm{MoO}}_{4}$ is isostructural to the unconventional superconductor ${\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}$ but with two electrons instead of two holes in the $\mathrm{Mo}/\mathrm{Ru}\text{\ensuremath{-}}{t}_{2g}$ orbitals. Both materials are Hund's metals, but while ${\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}$ has a van Hove singularity in close proximity to the Fermi surface, the van Hove singularity of ${\mathrm{Sr}}_{2}{\mathrm{MoO}}_{4}$ is far from the Fermi surface. By using density functional plus dynamical mean-field theory, we determine the relative influence of van Hove and Hund's metal physics on the correlation properties. We show that theoretically predicted signatures of Hund's metal physics occur on the occupied side of the electronic spectrum of ${\mathrm{Sr}}_{2}{\mathrm{MoO}}_{4}$, identifying ${\mathrm{Sr}}_{2}{\mathrm{MoO}}_{4}$ as an ideal candidate system for a direct experimental confirmation of the theoretical concept of Hund's metals via photoemission spectroscopy.