Cooperative interactions govern the fermiology of the polar metal Ca3Ru2 O7

Abstract

The antiferromagnetic Ruddlesden-Popper ruthenate Ca3Ru2O7 is a model polar metal, combining inversion symmetry breaking with metallic conductivity; however, its low-temperature (T<48K) crystal structure and Fermi-surface topology remain ambiguous despite numerous measurements and theoretical studies. Here we perform both first-principles calculations with static correlations and angle-resolved photoelectron spectroscopy experiments to construct a complete model of Ca3Ru2O7, reconciling inconsistencies among interpretations of electrical transport, thermopower measurements, and momentum- A nd energy-resolved band dispersions. The solution relies on treating the interplay among Coulomb repulsion, magnetic ordering, spin-orbit interactions, and the RuO6 octahedral degrees of freedom on equal footing. For temperatures 30 <30K, exhibiting charge- A nd spin-density waves from enhanced Coulombic interactions.