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arXiv · 1904.07625

Orbitally selective breakdown of Fermi liquid quasiparticles in Ca$_{1.8}$Sr$_{0.2}$RuO$_4$

Denys Sutter·Minjae Kim·Christian Matt·Masafumi Horio·Rosalba Fittipaldi·Antonio Vecchione·Veronica Granata·Kevin Hauser·Yasmine Sassa·Gianmarco Gatti·Marco Grioni·Moritz Hoesch·Timur Kim·Emile Rienks·Nicholas Plumb·Ming Shi·Titus Neupert·Antoine Georges·Johan Chang
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Abstract

We present a comprehensive angle-resolved photoemission spectroscopy study of Ca$_{1.8}$Sr$_{0.2}$RuO$_4$. Four distinct bands are revealed and along the Ru-O bond direction their orbital characters are identified through a light polarization analysis and comparison to dynamical mean-field theory calculations. Bands assigned to $d_{xz}, d_{yz}$ orbitals display Fermi liquid behavior with fourfold quasiparticle mass renormalization. Extremely heavy fermions - associated with a predominantly $d_{xy}$ band character - are shown to display non-Fermi-liquid behavior. We thus demonstrate that Ca$_{1.8}$Sr$_{0.2}$RuO$_4$ is a hybrid metal with an orbitally selective Fermi liquid quasiparticle breakdown.

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Denys Sutter, Minjae Kim, Christian Matt, Masafumi Horio, Rosalba Fittipaldi, Antonio Vecchione, Veronica Granata, Kevin Hauser, Yasmine Sassa, Gianmarco Gatti, Marco Grioni, Moritz Hoesch, Timur Kim, Emile Rienks, Nicholas Plumb, Ming Shi, Titus Neupert, Antoine Georges, Johan Chang. 2019-04-16. Orbitally selective breakdown of Fermi liquid quasiparticles in Ca$_{1.8}$Sr$_{0.2}$RuO$_4$. https://doi.org/10.1103/physrevb.99.121115

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