In this work, magnetization dynamics is studied in superconductor-ferromagnet-superconductor threelayered films in a wide frequency, field, and temperature ranges using the broad-band ferromagnetic resonance measurement technique. It is shown that in the presence of both superconducting layers and of superconducting proximity at both superconductor-ferromagnet interfaces a massive shift of the ferromagnetic resonance to higher frequencies emerges. The phenomenon is robust and essentially long-range: it has been observed for a set of samples with the thickness of ferromagnetic layer in the range from tens up to hundreds of nanometers. The resonance frequency shift is characterized by proximity-induced magnetic anisotropies: by the positive in-plane uniaxial anisotropy and by the drop of magnetization. The shift and the corresponding uniaxial anisotropy grow with the thickness of the ferromagnetic layer. For instance, the anisotropy reaches 0.27 T in experiment for a sample with a 350-nm-thick ferromagnetic layer, and about 0.4 T in predictions, which makes it a ferromagnetic film structure with the highest anisotropy and the highest natural resonance frequency ever reported. Various scenarios for the superconductivityinduced magnetic anisotropy are discussed. As a result, the origin of the phenomenon remains unclear. Application of the proximity-induced anisotropies in superconducting magnonics is proposed as a way for manipulations with a spin-wave spectrum.

Josephson vortices play an essential role in superconducting quantum electronics devices. Often seen as purely conceptual topological objects, 2 π -phase singularities, their observation and manipulation are challenging. Here we show that in Superconductor—Normal metal—Superconductor lateral junctions Josephson vortices have a peculiar magnetic fingerprint that we reveal in Magnetic Force Microscopy (MFM) experiments. Based on this discovery, we demonstrate the possibility of the Josephson vortex generation and manipulation by the magnetic tip of a MFM, thus paving a way for the remote inspection and control of individual nano-components of superconducting quantum circuits.

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The specific heat cp and magnetization of single crystal hexagonal manganites of the type Yb1−xCaxMnO3 (x = 0, 0.05, and 0.10) were measured in a wide temperature range as a function of magnetic field. Antiferromagnetic ordering of the Mn sublattice occurs at TN = 83 K. Ca doping has surprisingly minimal effect on the magnetic properties. At low temperature (∼3.5 K), all compounds show ferromagnetic (FM) ordering in the basal plane attributed to Yb in site 2a. For low fields applied along the c direction, Yb spin reorientation occurs and FM ordering disappears. cp shows a broad maximum centered at the temperature ∼6 K that is consistent with a Schottky anomaly related to the Zeeman splitting of the Yb moments due to Mn molecular field. In the field of 30 kOe, the re-entrant FM transition takes place with Yb ions in sites 2a and 4b.