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| 2DSOTECH – Dvojrozmerná van der Waalsovská spinovo-orbitálna torzná technológia | |
| 2Dimensional van der Waals Spin-Orbit Torque Technology | |
| Program: | ERANET |
| Project leader: | RNDr. Gmitra Martin, PhD. |
| Annotation: | Engineering two-dimensional (2D) material van der Waals heterostructures by combining the best of different functional constituents can offer a plethora of opportunities in nanoelectronics. Here, we propose to develop all-2D spintronics platforms for the next generation of information technology based on 2D magnetic and topological spin-orbit materials. These hybrid systems can provide a strong synergy between spintronics and 2D materials, with the goal of combining “the best of both worlds”. Such integration of spin-orbit physics and magnetism in 2D heterostructures will enable groundbreaking functionalities in all-2D spin-orbit torque (SOT) technologies for low-power and non-volatile memory and logic devices.We will exploit low crystal symmetry of layered spin-orbit materials (SOM), hosting novel spin textures for the realization of efficient charge-to-spin conversion (CSC) with a significant out-of-plane spin-orbit field contribution for SOT technologies. We will start with basic investigation of CSC by using potentiometric methods in non-local spin valve geometry with graphene heterostructures. These studies will provide information about the main driving mechanisms of the CSC phenomena, such as the spin Hall, Rashba-Edelstein, or other spin-momentum locking effects to generate a giant and tunable spin polarization. Magnetic 2D crystals, on the other hand, exhibit a wide range of magnetic ordering and, extraordinarily, have the potential to be controlled by purely electronic means. Here, we will investigate 2D magnets for SOT technologies exploiting their low-dimensionality, perpendicular magnetic anisotropy, and the possibility of electric field control. We will examine the dynamics of magnetic excitations, their anisotropies, and controllability by gates, the critical parameters influencing the magnetic switching speed.This project will integrate 2D magnets and SOMs with engineered interfaces to establish exceptionally efficient SOT switching functionalities in all-2D materials platforms. We aim to study the fundamentals of magnetization dynamics and SOT switching behavior of hybrid structures using electronic, magnetotransport, time and spatially resolved magneto-optics, ferromagnetic resonance and 2nd harmonic measurements. The potential of the novel functionalities in these heterostructures will arise from the interplay of exotic spin textures, magnetic phases, proximity-induced exchange and spin-orbit effects at the interfaces of the 2D materials. These effects will be further controlled by interface engineering with a graphene interlayer, twist angle between the layers, and with external parameters such as electric field and pressure. These functionalities will be complemented with voltage-controlled magnetization switching in ultrathin devices. Finally, we will utilize these engineered hybrid devices to demonstrate ultra-fast and low-power magnetization switching of 2D magnets, for a future generation of all-2D SOT technologies. |
| Duration: | 1.12.2021 – 29.11.2024 |
| Stavy tenzorových stietí Algoritmy a aplikácie | |
| Tenso-Network States Algorithms and Applications | |
| Program: | JRP |
| Project leader: | RNDr. Vargová Hana, PhD. |
| Duration: | 1.1.2021 – 31.12.2022 |
| MMVVM – Magnetické a magnetooptické vlastnosti vybraných manganitov. | |
| Magnetic and magnetooptical properties of selected manganites. | |
| Program: | Bilateral – other |
| Project leader: | RNDr. Mihalik Matúš, PhD. |
| Annotation: | Chemical compounds of the composition RTO3 (R = rare earth, T = Mn, Fe) attract the attentionof the physicists because of their very interesting physical properties like multiferroicity, magneticordering succeeded by the compensation temperature, high application potential in field of themagnetocaloric effect at room temperature, magnetooptical applications in THz region, orinteresting catalytic properties. Our project is focused to the deeper understanding andclarification of the selected physical properties of the RMn1-xFexO3 compounds, which will beprepared in the single-crystal form by the float zone method in the optical mirror furnace. Thesubstitution of Mn for Fe ions allows the tuning of the magnetic interactions in this system. Theprepared oxides will be subsequently characterized from the point of view of structural,magnetic, optic and magnetooptic properties. The big motivation to submit this project for theboth partner organizations is the effort to start bilateral collaboration between the scientificgroups in the area of the study of new materials. This collaboration allows the mobility mainly forPhD. students and postdoctoral fellows on the both sites. |
| Duration: | 1.1.2015 – 31.12.2015 |
National
| PRESPEED – Perspektívne elektrónové spinové systémy pre budúce kvantové technológie | |
| Perspective electronic spin systems for future quantum technologies | |
| Program: | SRDA |
| Project leader: | RNDr. Vargová Hana, PhD. |
| Annotation: | The project is aimed at a comprehensive understanding of possibilities and limiting factors of electron spin systems for a quantum computation and quantum information processing, which will be investigated by the combination of advanced analytical and numerical methods including among others exact mapping transformations, localized-magnon theory, exact diagonalization, tensor-network methods, density functional theory, Monte Carlo simulations and density-matrix renormalization group method. In particular, we will examine the possibility to stabilize a bipartite and multipartite entanglement as a genuine quantum phenomenon needed for a quantum computation and quantum information processing at least up to temperature of liquid nitrogen or preferably room temperature. We will also explore the capability of the pulsed electron spin resonance for the spin-qubit manipulation. Quantum spin systems with topologically protected edge states eligible for a topological quantum computation will be investigated in detail together with a few selected quantum spin chains studied in connection with the implementation of a quantum teleportation. Frustrated Heisenberg spin systems supporting either the presence of a nontrivial skyrmion phase or magnon-crystal phases will be investigated in connection with the possibility to store a quantum information or to implement more complex quantum circuits. Heterostructures composed of atomically thin layers coupled by van der Waals forces will be examined with respect to a superconducting pairing and topological quantum computation. The studied electron spin systems will be either motivated by the effort to understand unconventional behavior of existing real magnetic materials or will be supplemented by the respective proposals for their experimental realization. |
| Duration: | 1.7.2021 – 30.6.2025 |
| Teoretické štúdium multifunkčných kvantových nízko-rozmerných magnetických materiálov | |
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| Program: | VEGA |
| Project leader: | RNDr. Vargová Hana, PhD. |
| Annotation: | Multifunctional magnetic materials represent an ideal platform for nowadays technological demands. Reduceddimensions drag out their quantum properties opening thus new paradigms for possible utilization. The projectaims to study exotic quantum states in low-dimensional magnetic materials. We plan to utilize first principlescalculations based on density functional theory with the aim to propose and solve realistic effective quantum spinmodels for representative systems, which exhibit an enhanced magnetoelectric and/or barocaloric response in a vicinity of classical or quantum phase transitions. The present proposal focuses on frustrated quantumHeisenberg spin systems with flat bands appearing due to a destructive quantum interference, magnon-crystalphases (Wigner crystal of magnons) relevant for technological applications and one-dimensional quantum spin chains suitable for quantum information processing. |
| Duration: | 1.1.2020 – 31.12.2023 |
| EXSES – Exotické kvantové stavy nízkorozmerných spinových a elektrónových systémov | |
| Exotic quantum states of low-dimensional spin and electron systems | |
| Program: | SRDA |
| Project leader: | RNDr. Vargová Hana, PhD. |
| Annotation: | The project is devoted to theoretical study of low-dimensional quantum spin and electron systems, which will beexamined by the combination of advanced analytical and numerical methods including among other mattersexact mapping transformations, transfer-matrix method, strong-coupling approach, classical and quantum MonteCarlo simulations, exact diagonalization and density-matrix renormalization group method. The obtainedtheoretical outcomes will contribute to a deeper understanding of exotic quantum states of spin and electronsystems such as being for instance different kinds of quantum spin liquids as well as quantum states with asubtle long-range order of topological character or with a character of valence-bond solid. The project willsignificantly contribute to a clarification of unconventional magnetic behavior of selected low-dimensionalmagnetic materials and thus, it will have significant impact on a current state-of-the-art in the field of condensedmatter physics and material science. On the other hand, a detailed investigation of quantum entanglement willestablish borders of applicability of the studied spin and electron systems for the sake of quantum computationand quantum information processing. Another important outcome of the project is to clarify nontrivial symmetriesin tensor states of the strongly correlated spin and electron systems affected by either position dependentinteractions or changes in lattice geometries, which induce phase transitions of many types. |
| Duration: | 1.7.2017 – 30.6.2021 |
| Magnetoelektrický a magnetokalorický jav v exaktne riešiteľných mriežkovo-štatistických modeloch | |
| Magnetoelectric and magnetocaloric effect in exactly solvable lattice-statistical models | |
| Program: | VEGA |
| Project leader: | RNDr. Vargová Hana, PhD. |
| Annotation: | Magnetoelectric and magnetocaloric effects will be examined in detail with the help of exactly solvablelattice-statistical models including Ising spin systems, Ising-Heisenberg spin systems and coupled spin-electronsystems, which consist of localized Ising spins and delocalized electrons. The primary goal of the project is toexplore an influence of external electric field on basic magnetic properties and an influence of external magneticfield on basic thermodynamic properties of the studied lattice-statistical models. A response of magnetic systemon a change of external electric and magnetic fields will be investigated mainly in a vicinity of phase transitions(including quantum ones), where particularly interesting behaviour can be expected. The rigorous theoreticalresults will contribute to a deeper understanding of both studied cooperative phenomena, what enables topropose a subsequent optimalization of technologically important properties of multifunctional materials andmagnetic refrigerants. |
| Duration: | 1.1.2016 – 31.12.2019 |
| LDQSS – Komplexné štúdium efektov v nízko-rozmerných kvantových spinových systémoch | |
| Complex study of effects in low-dimensional quantum spin systems | |
| Program: | SRDA |
| Project leader: | RNDr. Vargová Hana, PhD. |
| Annotation: | The project is devoted to the theoretical as well as experimental study of selected quasi-two-dimensional magnetically frustrated spin system, namely Cu(tn)Cl2 (tn=1,3 – diaminopropane).The complex study will be performed with a help of stage-of-the-art methods of theoreticalphysics based on the Density Functional Theory and experimental analyses, including the studyof magnetic, transport and mechanical properties. In theoretical analyses we will focus on thestudy of magnetic properties, influence of spin-orbit coupling and van der Waals interaction aswell as thermodynamics stability, lattice specific heat and last, but no least, elastic constants ofCu(tn)Cl2 compound. To investigate the presence of phase transition in real material thethermodynamics characteristics, like specific-heat behaviour, susceptibility, magnetization orthermal conductivity will be examined experimentally. The mechanical analysis will beconcentrate on examination of elastic properties, like Young modulus, Poisson ratio, thermalexpansion as well as the sample hardness. The obtained results will contribute to a deeperunderstanding of mechanisms leading to the unconventional phenomena in two-dimensional magnetically frustrated spin system and will help us to better understand the role of quantumfluctuations in these materials. |
| Duration: | 1.1.2017 – 31.12.2018 |
| Extrem II – Extrem II – Dobudovanie Centra pokročilých fyzikálnych štúdii materiálov v extrémnych podmienkach | |
| Extrem II – Center of advanced physical studies for materials in extreme conditions | |
| Program: | EU Structural Funds Research & Development |
| Project leader: | RNDr. Skyba Peter, DrSc. |
| Duration: | 28.8.2010 – 31.1.2014 |
| Štúdium korelačných efektov v silne interagujúcich sústavách fermiónov | |
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| Program: | VEGA |
| Project leader: | RNDr. Farkašovský Pavol, DrSc. |
| Duration: | 1.1.2010 – 31.12.2012 |
| EXTREM I – Extrem – Centrum pokročilých fyzikálnych štúdií materiálov v extrémnych podmienkach | |
| Extrem – Center of advanced physical studies for materials in extreme conditions | |
| Program: | EU Structural Funds Research & Development |
| Project leader: | RNDr. Skyba Peter, DrSc. |
| Duration: | 19.5.2009 – 30.4.2011 |
| Štúdium nábojového a magnetického usporiadania v korelovaných sústavách elektrónov | |
| The study of charge and magnetic ordering in correlated electron systems | |
| Program: | VEGA |
| Project leader: | RNDr. Farkašovský Pavol, DrSc. |
| Annotation: | We will study a formation of charge and magnetic ordering in correlated electron systems consisting of two interacting subsystems: the itinerant d-electron subsystem and the localized subsystem of f-electrons or spins. The generating model for a description of such systems will be the spin-one-half Falicov-Kimball model generalized by the spin dependent interaction between d and f electrons (spins) and the Hubbard interaction between the itinerant d-electrons. The main goal is to contribute to understanding the formation of inhomogeneous charge and magnetic ordering, observed experimentally, for example, in the normal phase of high-temperature supreconductors (but also in many others rare-earth and transition metal compounds, e.g. NaxCoO2) as well as to contribute to the theory of itinerant magnetism, electronic ferroelectricity and the theory of metal-insulator transitions that are tightly bound with particular charge and magnetic ordering. |
| Duration: | 1.1.2007 – 31.12.2009 |