ABSTRACT. My presentation will be divided into a theoretical part and an applied part. Speaking about surprises of wave-particle duality, I will first compare quantum mechanics of photons and relativistic particles. I will introduce a photon-like dispersion relation for relativistic particles corresponding to the energy conservation equation of Einstein's special relativity. Using this dispersion relation, I will briefly show how the Dirac, Schrödinger, and Maxwell equations can be derived and what is the connection between them. In the application-oriented section, I will discuss our progress in laser printing techniques suitable for creating complex material structures via two-photon polymerization, as well as for printing very small and delicate objects—such as nanoparticles, biomaterials, living cells, and microorganisms. I will consider a few application examples of these technologies for printing of metasurfaces and development of 3D brain models.

ABSTRACT. The interpretation of ultraviolet (UV) spectral responses recorded from naturally oxidized metal surfaces is challenging because the measured signal can depend on surface condition, oxide inhomogeneity, sample geometry, reflection, scattering, baseline correction, and residual short-scale variability after Savitzky–Golay smoothing. Effective UV spectra of aluminium, copper, brass, lead, titanium, steel, nickel, cobalt, and iron were analysed using a constrained phenomenological Drude–Lorentz-type representation. Models containing one to five resonant terms were fitted and compared using R², RMSE, AIC, BIC, ΔBIC, signal-to-noise ratio, parameter plausibility, and residual error relative to an estimated variability scale. For each material, four spectra were saved under the same instrumental settings. We interpolated the spectra onto a common wavelength grid and then calculated their mean. All signed values exported by SpectraWiz in ABSOR mode were kept, including negative values associated with background and reference correction. No smoothing was applied during acquisition. In MATLAB, the averaged spectrum was smoothed with a second-order, 99-point Savitzky–Golay filter, while the unsmoothed mean remained visible in the main plots. The insets show how the same data appear in SpectraWiz when negative values are clipped at zero. These clipped values were used for display only and did not enter any calculation. We examined material-specific models ranging from DL-3 to DL-5 and compared them with simpler alternatives. The comparison included R², RMSE, AIC, BIC, ΔBIC, convergence across multiple starting points, parameter-bound warnings, and the response to changes in the smoothing window. All 15 starting points converged for every reported fit, although several parameters reached or approached their allowed limits. For this reason, the fitted coefficients are used here as practical descriptors of the measured metal–oxide surface response, not as unique values for free-carrier, interband, or oxide-related processes. They should not be interpreted as intrinsic optical constants of the investigated materials.

ABSTRACT. Laser induced breakdown spectroscopy (LIBS) offers rapid multi element analysis but suffers from shot to shot variability, spectral overlap, and resolution limits that complicate material identification. This study introduces a reproducibility aware workflow for spectral fingerprinting of nine metallic materials (Al, Brass, Cu, Co, Fe, Pb, Ni, Stainless Steel, Ti) using a Q switched Nd:YAG laser (1064 nm, 7 ns, ~70 mJ) and a moderate resolution UV spectrometer (200–400 nm, ~0.20 nm FWHM) (Fig 1). A dataset of 181 single shot spectra was baseline corrected and normalized. Reproducibility was quantified via replicate correlation, spectral entropy, resolution constrained peak counts, and a spectral stability index. Principal component analysis explained 63.55% of variance with PC1 and PC2, revealing class associated covariance patterns. Hierarchical clustering grouped copper with brass and iron with stainless steel, consistent with compositional similarities. Random Forest classification achieved complete separation under out of bag resampling, while stricter leave one signature out validation yielded 93.37% weighted accuracy. Negative control permutation tests confirmed statistical significance (empirical p = 0.00498). Importantly, acquisition metadata alone predicted material above chance (mean balanced accuracy 37.61%), indicating measurable confounding. Normalized spectra exhibited strong class specific structure, whereas raw single-shot intensities were more variable. Internal separability was demonstrated even in a restricted subset of unsmoothed spectra, though generalization to independent specimens or alloy grades remains unverified. This work highlights the methodological value of reproducibility aware spectral fingerprinting in LIBS. Rather than claiming external identification, the study establishes a transparent baseline for evaluating spectral reproducibility, covariance structure, and machine learning separability in metallic materials. The workflow provides a foundation for future studies involving independent samples, alloy discrimination, and externally validated predictions.

ABSTRACT. A coupled Particle-in-Cell (PIC) and Monte Carlo simulation workflow is being developed to investigate laser-driven proton–boron interactions using an 11B-enriched boric-acid catcher. Reliable transfer of the proton source to subsequent radiation-transport calculations requires sufficient independence from numerical particle sampling and observation time. Here, the numerical stability of a Smilei-based 1D3V proton-source model is investigated using two otherwise identical simulations with different particle-per-cell (PPC) resolutions. Previously generated HDF5 diagnostics were reanalysed without rerunning the simulations. The analysis considers statistical-weight distributions, high-energy proton populations, energy accounting, and rear-screen observables. The results show that the global in-box proton population and energy-related quantities are relatively insensitive to PPC variation, with consistent energy accounting between the simulations. In contrast, larger differences are observed in the cumulative rear-screen signal and its characteristic proton energy. Temporal analysis further indicates that the rear-screen signal continues to evolve significantly near the simulation endpoint. These findings demonstrate that particle-sampling and temporal convergence cannot yet be considered independently for the experimentally relevant rear-screen observables. Direct transfer of the current screen spectrum to the Monte Carlo stage could therefore introduce an artificial dependence on simulation duration and PPC resolution. A longer paired PIC continuation is consequently required before final proton-source observables are extracted. The proposed convergence assessment provides a reproducible framework for reliable PIC-to-Monte-Carlo source transfer in prospective proton–boron fusion studies.

ABSTRACT. Laser-induced plasma synthesis has emerged as a powerful bottom-up approach for the fabrication of high-purity quantum materials with precisely controlled structural, electronic, and optical properties. This presentation reviews recent advances in laser ablation and laser pyrolysis techniques for producing nanoscale materials tailored for next-generation technologies. Particular emphasis is placed on the synthesis of quantum materials for high-efficiency photovoltaic devices, spintronic structures, and quantum computing components, including quantum dots and nitrogen-vacancy (NV) centers. The presentation highlights how laser-induced plasma processing enables atomic-level control of material properties, offering new opportunities for scalable quantum information technologies and sustainable green energy applications.

ABSTRACT. Quantum information science is transforming the future of intelligent infrastructures by integrating quantum computing, quantum communication, quantum sensing, and artificial intelligence into next-generation cybersecurity systems. This presentation introduces the concept of Quantum Cognitive Security Systems (QCSS), an analytical framework that combines quantum information processing with adaptive cognitive architectures capable of autonomous threat detection, predictive analysis, and intelligent decision-making. The proposed framework explores the transition from conventional cybersecurity to hybrid quantum–classical infrastructures, emphasizing quantum-secure communications, distributed quantum sensing, quantum-enhanced machine learning, and post-quantum security. The presentation highlights how these technologies can contribute to resilient, adaptive, and autonomous security ecosystems for future cyber-physical infrastructures, providing new perspectives on the convergence of quantum information science, intelligent systems, and advanced cybersecurity.

ABSTRACT. Ga incorporation into wide-band-gap oxide hosts provides a route for controlling local electronic structure and band-edge character without introducing a vacuum-isolated nanostructure. Here we investigate substitutional Ga in corundum α-Al₂O₃ as an atomistic model of a chemically confined Ga-rich region. A 30-atom α-Al₂O₃-derived supercell containing 12 cation sites and 18 O atoms was considered, with two Al atoms replaced by Ga (16.7% of the cation sublattice). First-principles calculations were performed with Quantum ESPRESSO using the PBE generalized-gradient exchange-correlation functional, plane-wave basis sets, and PAW pseudopotentials. The pristine host was optimized by variable-cell relaxation, after which three nonequivalent Ga-pair arrangements were relaxed at fixed cell parameters. Converged SCF and NSCF calculations were followed by total and projected density-of-states analysis and real-space analysis of the band-edge wavefunction densities. The three Ga-pair arrangements remain insulating but differ in relative stability. The nearest-pair configuration (configuration B) is the lowest-energy structure, lying 18.5 meV per cell below the far-pair configuration and 114.9 meV per cell below the intermediate-separation configuration. For this preferred structure, the final high-accuracy NSCF calculation yields an indirect PBE Kohn-Sham gap of 5.0865 eV. The valence-band maximum corresponds to band 82 at k = (0,0,±1/3), whereas the conduction-band minimum is band 83 at Γ. The DOS/PDOS analysis shows that the upper valence band is dominated by O-p states, while the conduction-band onset is substantially modified by Ga-derived and neighboring cation contributions. Deep Ga-d states occur well below the valence-band edge and do not control the fundamental gap. Selected-state real-space densities provide a complementary spatial picture: the VBM density is concentrated predominantly around oxygen sites, whereas the CBM density is distributed over the local Ga–O coordination environment and adjacent cation network rather than being confined to the two Ga atoms. No isolated mid-gap states are found in the preferred configuration. These results indicate that substitutional Ga primarily restructures the conduction manifold while leaving the oxygen-derived valence edge comparatively host-like. The energetic preference for the near Ga pair further suggests that local chemical environment and cation-cation arrangement are important control parameters for band-edge engineering in corundum Al–Ga oxides. The absolute band-gap value is reported at the semilocal PBE level; the central conclusions of the present work concern internally converged configuration energetics and the orbital and spatial character of the band edges. The results provide an atomistic basis for designing chemically embedded Ga-rich regions and oxide heterostructures in which electronic confinement is governed by local composition and bonding.

ABSTRACT. Abstract

Gallium oxide (Ga₂O₃) and zinc oxide (ZnO) are wide-bandgap semiconductors with significant potential for next-generation electronic and memristive devices. In this work, Ga₂O₃/ZnO heterostructures were fabricated using low-temperature magnetron sputtering in a modernized vacuum system that enabled sequential deposition of oxide thin films within a single technological process without breaking the vacuum The heterostructures were deposited on sapphire and silicon substrates under different fabrication conditions. Their physical properties, including surface roughness and work function, were investigated, while structural and optical characterization was performed to evaluate the quality of the deposited oxide films. A memristive device based on the Ga₂O₃/ZnO heterostructure was then fabricated, and its current–voltage (I–V) characteristics were analyzed to assess its resistive switching behavior. The experimental results demonstrate that the fabricated Ga₂O₃/ZnO heterostructure exhibits promising memristive properties and has strong potential for integration into future micro- and nanoelectronic devices. These findings highlight the suitability of oxide heterostructures fabricated by low-temperature magnetron sputtering for the development of emerging non-volatile memory technologies.

ABSTRACT. A summary of the recent work of our group related to the methods and techniques to monitor stress and stress distribution in steels is provided in this presentation, based on the monotonic dependence of localized stress or microstrain on magnetic properties. To monitor stresses, the first challenge is to create and maintain stresses in reference steel samples, called steel coupons. The second challenge is to choose the proper magnetic properties offering monotonic dependence on stresses and determine the proper instrumentation for this reason. Having met these challenges, we were able to monotonically correlate magnetic properties with stresses and develop the so-called Magnetic Stress Calibration (MASC) curve, which is unique for each steel grade. Furthermore, there is strong evidence of a universality law governing the MASC curves of steel grades, after normalizing the stress or strain axis with the yield stress or strain, as well as the magnetic property axis with the corresponding maximum amplitude. The universality law allows for the fast and reliable determination of the MASC curve of an unknown steel grade, just by determining the yield point and the maximum value of the magnetic property monitored for the given steel grade. Finally, new measurements are demonstrated related to austenitic steels health monitoring.

ABSTRACT. Heating of plasma electrons in inertial fusion is crucial ([1–5]). In this work, plasma electron energization near and up to the critical point (z=zcr), in the region of collisionless shock formation and prior to it, is numerically simulated using s- and p-polarized laser pulses. When only the Gaussian precursor of the laser pulse has reached the critical point, two maxima of electron energization are observed: one within the body of the main laser pulse and another near the critical region. The simulations show that energization initiates at the critical points of small-scale periodic cavities. Maximum energization of low-density electrons occurs inside these cavities due to a trapped laser field with a spatial extent of approximately half the laser wavelength. A region of elevated energy forms around the cavities and subsequently expands. On ion timescales, the cavity size becomes larger than it was at the electron timescales of their formation. For s-polarization, the spatial distribution of electron energy mirrors the pattern of electron-density perturbations: energy is periodically modulated along the target surface, and regions of similar energy extend toward the critical point. After the cavities transform into a uniform, surface-parallel channel, intense energization develops within this channel. Once the main laser pulse reaches the critical point, a single maximum of enhanced electron energy forms. This region spans plasma densities from one quarter of the critical density (ncr/4) to the critical area. Laser-pulse expansion and strong electron energization begin near ncr/4. With a p-polarized pulse, a layered structure in the electron-energy distribution is observed at and just before the critical region; these layers align with isodensity surfaces. Rest of the region extending from ncr/4 to the critical area is characterized by three-dimensional, small-scale energization. As the main p-polarized pulse approaches the critical area, the number of layers decreases, while the extent of the 3D small-scale energization region increases.

ABSTRACT. Ultralight dark matter (ULDM) has emerged as one of the most promising alternatives to the standard cold dark matter paradigm. ULDM offers a remarkable example of macroscopic quantum physics in the Universe. Because of the extremely small mass of ultralight bosons 10-(21-22) eV, their de Broglie wavelength may reach astrophysical (kiloparsec) scales, allowing quantum coherence over galactic cores. As a consequence, dark matter behaves as a Bose-Einstein condensate whose macroscopic dynamics is governed by the generalized Gross-Pitaevskii equation coupled to gravity. Such a description naturally combines concepts originating from cosmology, condensed matter physics, wave mechanics, and nonlinear dynamics.

In this work, we investigate the orbital evolution of globular clusters in the Fornax dwarf spheroidal galaxy. Their observed distribution provides a sensitive probe of the dark matter density profile through the action of dynamical friction, which can be understood as the loss of kinetic energy by a globular cluster due to the gravitational wake it excites in the surrounding dark matter. This process is closely analogous to the energy dissipated by a ship moving through water, where part of its kinetic energy is transferred to the generation of surface waves. Particular attention is devoted to the long-standing Fornax timing problem, namely the apparent survival of several globular clusters at large galactocentric distances despite the expected orbital decay.

Particular attention is devoted to the long-standing Fornax timing problem, namely the apparent survival of several globular clusters at large galactocentric distances despite the expected orbital decay. We extend previous studies by incorporating the dissipation term appearing in the generalized Gross-Pitaevskii equation. We demonstrate that this damping term suppresses the gravitational density perturbations responsible for dynamical friction, reducing the drag force and increasing the orbital decay time.

Numerical simulations are performed for both weakly and strongly self-interacting ULDM models using observational constraints on the Fornax dark matter halo. We demonstrate that the inclusion of the damping mechanism substantially enlarges the parameter space compatible with the observed properties of the globular cluster system. In particular, weakly self-interacting or nearly non-interacting ULDM naturally reproduces the observed evolution of GC3, while strongly self-interacting models remain viable provided the cluster formed at sufficiently large galactocentric distances.

These results demonstrate that globular cluster dynamics provides an efficient astrophysical laboratory for testing the microscopic properties of ultralight dark matter and illustrates the fruitful interplay between cosmology, Bose-Einstein condensate physics, and computational modeling.

REFERENCES [1] E Gorbar, E. V., Barabash, O. V., Gorkavenko, V. M., Korshynska, K., Momot, A. I., & Zaporozhchenko, A. O. (2026). Damping of Dynamical Friction Force in Self-Interacting Ultralight Dark Matter and Fornax Timing Problem. Classical and Quantum Gravity, 43, 155003. https://doi.org/10.1088/1361-6382/ae85a7 [2] Gorkavenko, V., Barabash, O., Gorkavenko, T., Korshynska, K., Teslyk, O., Zaporozhchenko, A., & Gorbar, E. (2026). The Vortex State of Ultralight Dark Matter and the Fornax Timing Problem. Universe, 12(2), 39. https://doi.org/10.3390/universe12020039

ABSTRACT. KM3NeT is a European Research infrastructure that is currently under construction at two locations in the Mediterranean Sea [1]. It has two major scientific goals: the discovery and observation of high-energy neutrino sources in the Universe and the determination of neutrino mass hierarchy through measurement of atmospheric neutrino oscillations. To achieve these goals, the KM3NeT collaboration is building 2 Cherenkov detectors: ARCA, a cubic kilometer size neutrino telescope, about 100 km off-shore Sicily, Italy, at a depth of about 3500 and the smaller ORCA telescope about 40 km off-shore Toulon, France, at a depth of about 2500 m. The KM3NeT project is based on experience from ANTARES detector [2], a first deep-sea neutrino telescope, which successfully operated for over 15 years before being dismantled in February 2022. The main detection element of the KM3NeT telescope is a digital optical module (DOM), a single 0.44 m diameter pressure-resistant glass sphere, comprising 31 three-inch photomultiplier tubes with sub-nanosecond timing accuracy and large dynamic range, calibration instruments and electronics for power, readout and data acquisition [2]. 18 KM3NeT DOMs form a string or detection unit, which is a deployable structure of the KM3NeT telescope. ARCA and ORCA strings have different distances between the DOMs and the length of the ARCA string is about 4 times larger than ORCA one. 115 detection units form the building block (BB) of KM3NeT. In the final configurations, ARCA and ORCA will be formed from two and one building blocks, respectively. Modular KM3NeT design allows data taking with the ARCA and ORCA detectors still in the construction stage. Collection, reconstruction and analysis of KM3NeT data are based on constant monitoring of the deep-sea environment, such as optical background, sea currents and water transparency. We report results obtained with ARCA detector, which operated with 21 detector units (378 DOMs). On 13 February 23, ARCA21 observed the most energetic neutrino ever detected [4]. This neutrino event, named KM3-230213A, was identified as a single muon that crossed the entire detector and induced signals in more than one third of the active DOMs. The energy of KM3-230213A was estimated to be about 220 PeV. This observation triggered several studies about the possible astrophysical origin of the KM3-230213A neutrino event. The second result includes atmospheric neutrino oscillation measurement with ORCA detector configuration comprising 6 detector units [5]. A high-purity sample of 5828 neutrino candidates was reconstructed in this configuration, corresponding to an exposure of 433 kton-year. The measured atmospheric neutrino oscillation parameters indicate ORCA capabilities for determining neutrino mass hierarchy.

ABSTRACT. At high level of doping and at high level of compensation, firstly impurity states may form an impurity band; and secondly, compensation defects in the concentration approximately the same as doping level may cause significant lowering of impurity ionization energy. Because of disorder caused by random variation of impurity potential the impurity band is broadened in comparison with the band formed in the case of perfect periodic distribution. The variation of impurity potential is related to random distribution of compensating defects and is in the range of ~ⅇ^2/R. where R is average distance between the impurities. This random potential causes tails in density of states, which correspond to localized state. The states until E_c¬(mobility edge) are localized. We modeled formation of impurity band taking into account lowering the impurity level by compensating defects and random variation of impurity potential. Interaction between the impurities and random variation of potential are described by Anderson model, where random variation of potential is modeled by variation of the depth of potential wells. To account the random variation of potential and get the density of state in the impurity band, we employ Monte Carlo simulations to statistically analyze the effects of white noise perturbations on the electronic energies. Using the approach it has been estimated electronic structure of phosphorous doped gallium oxide modelling an individual phosphorous impurity by one-dimensional rectangular potential well, and explained room temperature conduction, and the transition to an insulator state