Electronic Band Structure in Ruthenate Heterostructures

In this talk, we investigate the electronic band structure in quantum confined ruthenate heterostructures using soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES). The SX-ARPES at the Advanced Photon Source of Argonne National Laboratory enables high photoelectron depth to extract momentum-driven band structure inside the buried interfaces. This characteristic measurement is exploited to determine the charge concentration and charge distribution of our heterostructures as a function of overlayer thickness. The evolution of the core-level Fermi surface mapping of oxide heterostructures comprised of SrRuO₃ and SrTiO₃ atomic layers affirms the band modulation in these superlattices. We find interlayer coupling and Fermi surface engineering in this ultrathin epitaxial film counterpart of Sr₂RuO₄ can be controlled to potentially gain insight into unconventional superconductivity of ruthenates.