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Materials with AV3Sb5 (A = K, Rb, Cs) stoichiometry are recently discovered kagome superconductors with the electronic structure featuring a Dirac band, van Hove singularities, and flat bands. These systems undergo anomalous charge-density-wave transitions at T CDW ∼ 80 – 100 K, resulting in the reconstruction of the Fermi surface from the pristine phase. Although comprehensive investigations of the electronic structure via quantum oscillations (QOs) have been performed on the sister compounds CsV3Sb5 and RbV3Sb5, a detailed QO study of KV3Sb5 is so far absent. Here, we report the Shubnikov–de Haas QO study in KV3Sb5. We resolve a large number of new frequencies with the highest frequency of 2202 T (occupying ∼54% of the Brillouin zone area in the kx–ky plane). The Lifshitz-Kosevich analysis further gives relatively small cyclotron effective masses, and the angular dependence study reveals the two-dimensional nature of the frequencies with a sufficient signal-to-noise ratio. Finally, we compare the QO spectra for all three AV3Sb5 compounds collected under the same conditions, enabling us to point out the similarities and the differences across these systems. Our results fill in the gap of the QO study in KV3Sb5 and provide valuable data to understand the band structure of all three members of AV3Sb5. [ABSTRACT FROM AUTHOR]

Electron-electron (e-e) correlation and spin-orbit coupling (SOC) are two essential control parameters that determine the physical properties of transition-metal-oxide-based thin films and heterostructures. Here, by harnessing these two parameters, we report the systematic control of both ferromagnetism and in-plane magnetic anisotropy in La0.67Ca0.33MnO3/CaIr1-xRuxO3 (LCMO/CIRO) superlattices grown on NdGaO3 substrates. In these all-oxide epitaxial systems, we demonstrate that the e-e correlation and the SOC depend strongly on the chemical composition of CIRO layers. By simply increasing the Ru doping level x, we can significantly suppress the degradation of ferromagnetism in ultrathin LCMO layers and enhance the TC by ∼90 K. Moreover, we observe a clear reorientation of the magnetic easy axis from orthorhombic [010] to [100] as x decreased to 0, which may originate from the enhanced SOC. Our work provides an insight for utilizing the 4d/5d transition-metal-oxides to tune the functionality of magnetic heterostructures. [ABSTRACT FROM AUTHOR]