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| Supravodivosť v tenkých filmoch nitridov – materiály pre budúce kvatové zariadenia | |
| Superconductivity in nitride thin films – materials for future quantum devices | |
| Program: | Other |
| Project leader: | RNDr. Pristáš Gabriel, PhD. |
| Annotation: | The main aim of our common project is study superconductivity in nitride thin films. It was shown, that narrow NbN superconducting strips could be used forconstruction of ultrafast single photon detectors, which are expected to play important role in the secure quantum communications. Very recently, team from Montanuniversität Leoben succeeded in preparation of superconducting high entropy alloy (HEA) thin films and team from Slovak side preformed measurements of its superconducting properties. Preparation of nitride HEAs will be next step in effort to improve superconducting parameters of thin films for the purpose to be used in future quantum devices. |
| Duration: | 1.11.2023 – 31.10.2024 |
National
| STRIPEX – Vplyv dynamických nábojových pásov na kvantové magnety a supravodiče v extrémnych podmienkach | |
| Influence of dynamic charge stripes on quantum magnets and superconductors in extreme conditions | |
| Program: | SRDA |
| Project leader: | doc. RNDr. Gabáni Slavomír, PhD. |
| Annotation: | The project is aimed at solving the urgent fundamental problem of the genesis of the so-called of dynamic charge stripes (DCS) – inhomogeneous distribution of conduction electron oscillations – and their influence on the properties of strongly correlated electron systems (SCES). The charge stripes play an important role in the high-temperature superconductivity (HTSC) of cuprates and also underlie the mechanisms responsible for the colossal magnetoresistance in manganites, cobaltites, iron-based HTSCs, etc. Observing directly the effect of DCS on the scattering of charge carriers in the mentioned SCES is very sophisticated due to their complex composition, low symmetry of the crystal structure and high sensitivity to external conditions. Instead, it is suitable to use model SCES. Such model materials are rare earth dodecaborides (RB12) with Jahn-Teller structural instability and electronic phase separation on the nanoscale range, in which the appearance of dynamic charge stripes was reliably determined for the first time both for superconductors (ZrB12, LuB12) and for quantum magnets (R = Ho, Er, Tm). The comprehensive study of DCS will be extended by additional model systems based on hexaborides (RB6) and frustrated quantum magnets based on rare earth tetraborides (RB4), and will includes the influence of external extreme conditions such as very low temperatures, high magnetic fields and pressures. |
| Duration: | 1.7.2024 – 30.6.2028 |
| Necentrosymetrické supravodiče | |
| Non-centrosymmetric superconductors | |
| Program: | VEGA |
| Project leader: | RNDr. Kačmarčík Jozef, PhD. |
| Duration: | 1.1.2024 – 31.12.2027 |
| LSD – Nízkorozmerné supravodivé aparáty | |
| Low-dimensional Superconducting Devices | |
| Program: | SRDA |
| Project leader: | Mgr. Szabó Pavol, CSc. |
| Annotation: | Ultralow temperatures have become an important tool for new research avenues in nanoscience, materials research and particularly in quantum nanotechnologies. Scaling down a physical system towards the sizes when the quantum properties surpass classical physics opens a plethora of new quantum-driven effects, thus giving rise to new classes of quantum materials. Within the proposed project we will focus our study on low-dimensional quantum devices, heterostrucures consisting of atomically thin superconducting slabs and aditional layers with different order (inslulator, metal, ferromagnet). In such systems symmetries can be broken possibly allowing for non trivial topological quantum states relevant for future technologies. Atomically thin layered materials are systems with zero limit bulk-to-surface ratio. Their physical properties are strongly affected by interfacing with other systems. Therefore, they represent an accessible platform for the abundance of quantum effects that can be engineered by combining them into vertical stacks using exfoliation techniques. One identifies two types of layered systems – atomically thin artificially prepared van der Waals heterostructures [Science 353, aac9439 (2016)], and naturally layered three-dimensional crystal systems. A special class of naturally layered materials is misfit structures combining alternating atomic layers of hexagonal transition metal dichalcogenides and slabs of ionic rare-earth monochalcogenides in the same superlattice [APL Mater 10, 100901 (2022)]. They feature new state of quantum matter, the Ising superconductivity resulting from broken inversion symmetry and strong spin-orbit coupling as has been recently shown by us. The misfits are also exfoliative and thus incorporable as units in vertical stacks. |
| Duration: | 1.9.2024 – 31.12.2027 |
| ROTOLES – Optimalizovaný rast a transportné a optické vlastnosti tenkých vrstiev vybraných topologických polokovov | |
| Optimised growth and the transport and optical properties of thin layers of selected topological semimetals | |
| Program: | SRDA |
| Project leader: | prof. RNDr. Samuely Peter, DrSc., akademik US Slovenska |
| Annotation: | One of the fundamental results of quantum mechanics in the 1920s was the derivation of relativistic equations for massive fermions (Dirac), massless fermions (Weyl) and fermions that are themselves antiparticles (Majorana). Since those times, particle physics has been searching for particles representing Weyl and Majorana\’s fermions. However, their search has not yet been successful. In the last twenty years, it has been shown that the band structure of some materials has such unique characteristics that the charge carriers in them can behave according to the dynamics satisfying the Dirac or Weyl relativistic equations. Such materials include compounds from the group of transition metals dichalcogenides, which we will focus on in our project. We will work with very thin layers of selected materials from this group, such as PtSe2, MoTe2 and WTe2. The first step in the implementation of the project will be the preparation of such layers by chalcogenisation of thin films of transition metals. Their transport and optical properties will then be thoroughly investigated. Temperature-dependent transport measurements can show us transitions between different structures of the same material. We expect that a metal-insulator transition can be observed when the thickness of such thin films is varied. Some of these materials can go into a superconducting state at very low temperatures. We will also try to induce this state in close proximity, i.e. when the thin layer is in contact with another superconductor. Optical measurements will be correlated with transport measurements. We derive essential frequency-dependent characteristics, such as optical conductivity, from the latter. We will look for characteristics theoretically predicted for Dirac and Weyl fermions in the optical conductivity. |
| Duration: | 1.7.2024 – 30.6.2027 |
| MIKROKELVIN – Kvantové materiály pri ultra-nízkych teplotách – MIKROKELVIN | |
| Quantum matters at very low temperatures – MICROKELVIN | |
| Program: | Štrukturálne fondy EÚ Výskum a inovácie |
| Project leader: | RNDr. Skyba Peter, DrSc. |
| Duration: | 1.1.2020 – 30.6.2023 |