Temperature-dependent and Layer-specific Spin-resolved Electronic Structure of Ferromagnetic Triple-layer Sr₄Ru₃O₁₀

High resolution angle- and spin-resolved photoemission spectroscopy (ARPES) of the triple-layer ruthenate Sr₄Ru₃O1₀ has recently highlighted key electronic structure features important to its ferromagnetism [1]. Namely, two narrow spectral peaks ∽30 meV below the Fermi-level in two regions of the Brillouin zone, a hole-like band at the zone-center and a saddle-point van Hove singularity at the zone edge, exhibit almost 100\% but opposite-sign spin-polarization, and a dramatic Kondo-coherence-like temperature-dependent spectral weight variation. In this talk, we focus on the detailed quantitative comparison of the ARPES to spin-polarized DFT calculations which identify the specific origins of the narrow bands, and lead to a prediction of layer-specific opposite spin-polarization contributions to the magnetism, which is then experimentally evidenced in the ARPES multi-zone matrix element intensities. In addition, fine T-dependent effects at spin-majority zone corner bands, at spin-minority polarized oxygen bands, and at band crossings of zone-folded spin-minority and spin-majority bands at the saddle-point, provide a more complete picture of the itinerant versus localized description of its magnetism.

[1] P. Ngabonziza et al., arXiv:2305.07222 (2023).