Theoretical study of multifunctional quantum low-dimensional magnetic materials

Multifunctional magnetic materials represent an ideal platform for nowadays technological demands. Reduced
dimensions drag out their quantum properties opening thus new paradigms for possible utilization. The project
aims to study exotic quantum states in low-dimensional magnetic materials. We plan to utilize first principles
calculations based on density functional theory with the aim to propose and solve realistic effective quantum spin
models 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 quantum
Heisenberg spin systems with flat bands appearing due to a destructive quantum interference, magnon-crystal
phases (Wigner crystal of magnons) relevant for technological applications and one-dimensional quantum spin
chains suitable for quantum information processing.

Position: Principal Investigator
Project ID: VEGA 1/0105/20
Period: Jan 2020 – Dec 2023
supported by the Ministry of Education, Science, Research and Sport of the Slovak Republic

Exotic phenomena in frustrated spin systems

Frustration is present in a number of real magnetic materials and can result in a variety of unexpected
phenomena. The project aims to theoretically investigate exotic phenomena in selected types of frustrated spin
systems. In particular, we consider several antiferromagnetic systems on more (triangular, kagome) as well as
less (pentagonal, Shastry-Sutherland, trellis, Cairo pentagonal) conventional geometrically frustrated lattices.
They include classical and semi-classical systems ranging from one to three-dimensions both in the lattice
(1D-3D) and spin (Ising, XY and Heisenberg) spaces. We anticipate that unconventional geometries, dimensional
crossovers and/or additional types of interactions (nematic, antisymmetric) can lead to novel phases and/or exotic
critical behavior. Approaches based on an approximate scheme, applied in a broad parameter space, through
cutting-edge simulation techniques implemented on GPU to an exact solution in soluble cases are going to be
employed to tackle the task.

Position: Investigator
Project ID: VEGA 1/0105/99
Period: Jan 2019 – Dec 2022
supported by the Ministry of Education, Science, Research and Sport of the Slovak Republic

Dynamics of domain walls and skyrmions in thin magnetic layers

This project aims at deeper understanding the dynamics of complex spin textures of domain walls in thin wires and magnetic skyrmions in thin layers. Both of these fields of micro-magnetism are currently of high interest and of high impact on potential devices like smart sensors and memories that could substitute current technology. The main goal of this project is to use an innovative experimental technique based on magneto-optical Kerr effect that we have currently developed, to study surface magnetism of thin cylinders. Secondly, the motion of skyrmions in thin layers will be studied in thin multilayered films by magneto-optical methods. The role of spin-orbital torques on skyrmion displacement will be evaluated and the influence of surface roughness on magnetic properties of helical nano-magnets will be studied. The obtained result will be used for construction of a new class of magnetometers.

Position: Investigator
Project ID: APVV-17-0184
Period: 2018 – 2022
supported by the Ministry of Education, Science, Research and Sport of the Slovak Republic

Implementation of electronic structure methods in study of quantum materials

Aim of the project is to incorporate in a long-term perspective state-of-the-art research techniques of electronic structure calculations of quantum materials in existing portfolio of research activities at Department of Theoretical Physics and Astrophysics. The project aspire to enlarge field of research study involving recent topics of interlacing of electronic wave function and topological aspects in solids. Recent examples are quantum Hall effect, topological insulators, and topological superconductors characterized by nontrivial topologies of Hilbert space. The project considers most fundamental interactions in description of electronic structure, for instance, spin-orbit coupling which is as a key fundamental interaction allowing to manipulate spin of electrons — essential for spintronics applications. Direct manifestation of the quantum mechanics in solids are electrical polarization or magnetism opening miscellaneous properties of novel functional materials.

Position: Principal Investigator
Project ID: MSVVaS SR 90/CVTISR/2018
Period: Feb 2018 – Jan 2019
supported by the Ministry of Education, Science, Research and Sport of the Slovak Republic

Využitie spin-orbitálnych a magnetických proximálnych efektov pri dizajne nových funkcionálnych materiálov

Projekt je zameraný na štúdium spin-orbitálnych a magnetických proximálnych efektov vo van der Waalsovských heteroštruktúrach, v ktorých sú tieto efekty prakticky neprebádané. Zámerom projektu je popri návrhu teoretického opisu a pochopenia proximálnych efektov v heteroštruktúrach atómovo tenkých magnetických a nemagnetických vrstiev, je zachovať existujúce spolupráce a nadviazať nové kontakty ako bolo plánované v návrhu projektu EPREMA podaného v rámci výzvy H2020-MSCA-IF-2017 (#796349) a H2020-MSCA-IF-2018 (#843505), ktorý bol ocenený v oboch prípadoch certifikátom “Seal of Excellence”.

Position: Principal Investigator
Project ID: VVGS IPPH2020 VVGS-2018-887, VVGS-2019-1227
Period: July 2018 – June 2019, July 2019 – June 2020
supported by CCVaPP P. J. Šafárik University in Košice