1. Anharmonic quantum effects of implanted muons : route to probing nuclear quantum behavior in solidsFabian Hotz, Matjaž Gomilšek, Tina Arh, Thomas Hicken, Polona Umek, Andrej Zorko, Hubertus Luetkens, 2026, original scientific article Abstract: The quantum behavior of light particles in solids gives rise to phenomena that cannot be captured by a classical description. We show that muon spin spectroscopy (μSR), when paired with a quantum-mechanical treatment of the implanted muon, becomes a sensitive and direct probe of nuclear quantum effects. By modeling the muon as a spatially extended quantum particle, our approach captures strong anharmonic behavior. We demonstrate this in Zn-barlowite, which serves as a nontrivial test case due to its structurally complex lattice and the presence of both fluorine and hydroxyl groups. Our results establish a route for extracting nuclear quantum signatures from μSR data and open different opportunities for studying light nuclei such as hydrogen and lithium in systems where quantum fluctuations shape structure and function.
Keywords: defects, magnetic interactions, magnetization dynamics, spin dynamics, density functional theory, muon spin resonance
Published in DiRROS: 19.06.2026; Views: 266; Downloads: 196
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2. Preparation of dielectric layers for applications in digital microfluidic thermal switchesBlaž Velkavrh, Urban Tomc, Matej Šadl, Victor Regis de Moraes, Maja Koblar, Bianka Colarič, Andrej Kitanovski, Hana Uršič Nemevšek, 2024, original scientific article Keywords: dielectric layers, aerosol deposition method, spin-coating method, microfluidics, thermal switches
Published in DiRROS: 18.06.2026; Views: 149; Downloads: 245
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3. Oscillating topological charge for skyrmion-based spin-transfer torque nano-oscillatorVinko Sršan, Matej Komelj, Sašo Šturm, 2026, original scientific article Abstract: Magnetic skyrmions are considered as promising candidates for next generation information carriers. In cubic chiral magnets with bulk Dzyaloshinskii–Moriya interaction, skyrmions trivially extend into the third dimension forming so-called skyrmion string. The third dimension of skyrmion strings introduces an additional degree of freedom that can be utilized in skyrmion-based applications. An example of such application is spin-torque oscillator based on skyrmion breathing, gyrotropic motion and skyrmion deformation mechanisms. Expanding these mechanisms, we propose design of spin-torque oscillator based on topological charge oscillation in confined geometry where skyrmion string breathing, gyrotropic motion and skyrmion-edge interactions are coupled. Micromagnetic calculations were employed to demonstrate topological charge oscillation as a function of model geometries. It is shown that only a small subset of material geometries is suitable to obtain topological charge oscillations, indicating that precise engineering of geometry would be required to realize such a device. Findings presented in this work contribute to a better understanding of a skyrmion string dynamical phenomena, which offer additional route in designing spin-torque oscillators.
Keywords: magnetic skyrmions, skyrmion strings, micromagnetics, spin torque nano-oscillator
Published in DiRROS: 28.05.2026; Views: 165; Downloads: 179
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4. Antiferromagnetic Barkhausen noise induced by weak random-field disorderBosiljka Tadić, 2026, original scientific article Abstract: This study numerically investigates magnetization reversal processes driven by an external magnetic field in three-dimensional antiferromagnetic spin models with weak random-field disorder. Considering an extremely weak disorder and low temperature, we observe a stepwise hysteresis loop and the appearance of short magnetization bursts of a characteristic triangular shape; the number of bursts increases with disorder, indicative of Barkhausen-type noise. These phenomena are attributed to the simultaneous reversal at a given external field of segments composed of spins with identical neighborhoods. A local random field orients one or more spin neighbors, resulting in small, ferromagneticlike clusters distributed throughout the system. As disorder increases, these clusters may merge to form a labyrinthine structure within the antiferromagnetic background, facilitating brief avalanche propagation. The results demonstrate that, compared with familiar random-field ferromagnets, the observed antiferromagnetic Barkhausen noise and the related avalanche sequence have a profoundly different structure, organized into peaks associated with the transition between magnetization plateaus. They exhibit prominent cyclical trends and disorder-dependent multifractal fluctuations, with the singularity spectrum quantifying the degree of disorder. The activity avalanches exhibit scale invariance resembling that recently found in experiments with disordered ferr�magnets and martensites, as well as in quantum Barkhausen noise, which are associated with active geometric regions rather than individual-spin dynamics. The observed scaling behavior is interpreted in terms of self-organized critical dynamics.
Keywords: antiferromagnets, magnetization dynamics, numerical techniques, spin lattice models, Barkhausen noise
Published in DiRROS: 24.03.2026; Views: 334; Downloads: 272
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6. Academic entrepreneurs in Slovenia : entrepreneurial competences, intellectual property, and academic cultureAna Hafner, Janez Kolar, Urša Lamut, Karin Dobravc Škof, 2025, published scientific conference contribution Keywords: academic entrepreneurs, spin-outs, academic entrepreneurship, intellectual property, patents, entrepreneurial competences
Published in DiRROS: 03.02.2026; Views: 456; Downloads: 342
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7. Optimized flux single-crystal growth of the quantum spin liquid candidate ▫$NdTa_7O_{19}$▫ and other rare-earth heptatantalates, ▫$ErTa_7O_{19}$▫ and ▫$GdTa_7O_{19}$▫Lia Šibav, Matic Lozinšek, Zvonko Jagličić, Tina Arh, Panchanana Khuntia, Andrej Zorko, Mirela Dragomir, 2025, original scientific article Abstract: Single crystals are essential for characterizing a wide range of magnetic states, including exotic ones such as quantum spin liquids. This study reports a flux method for growing single crystals of NdTa7O19, the first quantum spin liquid candidate on a triangular spin-lattice with dominant Ising-like spin correlations. Purple NdTa7O19 single crystals with hexagonal morphology were successfully grown by using a K2Mo3O10–B2O3 flux. With lateral sizes up to 3.5 mm and a thickness up to 2 mm, these are the largest dimensions reported to date. The chemical composition was confirmed by powder and single-crystal X-ray diffraction along with scanning electron microscopy with energy dispersive X-ray spectroscopy. Aiming for an accurate determination of the magnetic anisotropy and its effect on the magnetic properties, NdTa7O19 crystals were additionally analyzed by magnetic susceptibility, revealing a substantial anisotropy without long-range magnetic ordering down to 2 K. Single crystals of two novel rare-earth heptatantalates, ErTa7O19 and GdTa7O19, were also grown, and their magnetic properties investigated. The magnetic anisotropy of ErTa7O19 closely resembles that of isostructural NdTa7O19, indicating the possibility of a similar exotic magnetic ground state. In contrast, GdTa7O19 shows paramagnetic behavior, consistent with previous results obtained for polycrystalline samples.
Keywords: quantum spin liquid, single-crystal growth, magnetic properties, flux, rare-earth tantalates
Published in DiRROS: 14.07.2025; Views: 853; Downloads: 599
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