We present a comprehensive angle-resolved photoemission spectroscopy study of Ca1.8Sr0.2RuO4. 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 dxz,dyz orbitals display Fermi liquid behavior with fourfold quasiparticle mass renormalization. Extremely heavy fermions - associated with a predominantly dxy band character - are shown to display non-Fermi-liquid behavior. We thus demonstrate that Ca1.8Sr0.2RuO4 is a hybrid metal with an orbitally selective Fermi liquid quasiparticle breakdown.
@article{arxiv.1904.07625,
title = {Orbitally selective breakdown of Fermi liquid quasiparticles in Ca$_{1.8}$Sr$_{0.2}$RuO$_4$},
author = {Denys Sutter and Minjae Kim and Christian Matt and Masafumi Horio and Rosalba Fittipaldi and Antonio Vecchione and Veronica Granata and Kevin Hauser and Yasmine Sassa and Gianmarco Gatti and Marco Grioni and Moritz Hoesch and Timur Kim and Emile Rienks and Nicholas Plumb and Ming Shi and Titus Neupert and Antoine Georges and Johan Chang},
journal= {arXiv preprint arXiv:1904.07625},
year = {2019}
}