National
CERBERUS – Farebné centrá v diamante – korelácia medzi atómovou štruktúrou a optoelektronickými vlastnosťami | |
Colour centres in diamond – correlation between atomic structure and opto-electronic properties | |
Program: | SRDA |
Project leader: | Ing. Varga Marian, PhD. |
Annotation: | The subject of the project is in the field of quantum technologies. We will prepare and characterize optically -activedefects in diamonds and correlate the atomic structures with optical properties to be used for quantum applicati ons.For a wide range of dopant concentrations, we will identify the dopant distributions and study the evolution ofdopants’ configuration in-situ, during thermal annealing, using atomic-resolution microscopy and spectroscopytechniques. We will further study the effect of annealing on the opto-electronic properties by measuringphotoluminescence, photocurrent and electroluminescence for the same set of samples. Graphene transparentelectrodes on a diamond surface will be fabricated for phototransport measurements. Diamond-based hybrid p-i-ndiodes will be prepared for electroluminescence measurements. We will focus on finding a correlation between theatomic structure and the opto-electronic properties of differently doped diamonds. This will contribute to theunderstanding of the fundamental relationship needed to efficiently design optically -active elements for diamondquantum devices. |
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: | Dr. rer. nat. Hulman Martin |
Annotation: | One of the fundamental results of quantum mechanics in the 1920s was the derivation of relativistic equations formassive 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 uniquecharacteristics that the charge carriers in them can behave according to the dynamics satisfying the Dirac or Weylrelativistic 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 firststep in the implementation of the project will be the preparation of such layers by chalcogenisation of thin films oftransition metals. Their transport and optical properties will then be thoroughly investigated. Temperaturedependent 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 ofthese materials can go into a superconducting state at very low temperatures. We will also try to induce this state inclose 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-dependentcharacteristics, such as optical conductivity, from the latter. We will look for characteristics theoretically predictedfor Dirac and Weyl fermions in the optical conductivity. |
Duration: | 1.7.2024 – 30.6.2027 |
Rast a optická charakterizácia 2D materiálov: MoTe2, WTe2, PtTe2 | |
Growth and optical characterization of 2D materials: MoTe2, WTe2, PtTe2 | |
Program: | VEGA |
Project leader: | RNDr. Pribusová Slušná Lenka, PhD. |
Annotation: | Research of thin-film materials noticed a significant increase, especially since the discovery of graphene, when a wide range of 2D materials began to study. A significant group of 2D materials is transition metal dichalcogenides(TMDs), including MoTe2, WTe2, and PtTe2. These materials have unique optoelectronic properties that varydue to the thickness of the layer and the crystal structure. Electrical properties vary depending on structures, fromsemiconducting to metallic. The preparation of films by tellurization of molybdenum, tungsten, and platinum ismore difficult than sulfurization or selenization due to the weaker redox properties of tellurium. The challenge in thin films is the controlled preparation of the required crystal structure of homogenous large-arealayers. This project aims to contribute to the solution of preparing these materials, characterize their structure and orientation of the films concerning the substrate, and determine the optical parameters and electrical properties. |
Duration: | 1.1.2023 – 31.12.2025 |
Štúdium dynamiky magnetického víru pre využitie v súčiastkach | |
Study of magnetic vortex dynamics for device applications | |
Program: | VEGA |
Project leader: | Ing. Šoltýs Ján, PhD |
Annotation: | In this project, we will focus on the theoretical and experimental investigation of magnetic vortices. The idea is touse them as a candidate for an information carrier in ultrafast and energy-efficient devices. The key idea of suchmemory is to use the two vortex core polarities as a magnetic bit that can be easily read and written via thedynamical reversal. We will search for the optimal shape of a magnetic 3D pattern with polarity easily controlledby a small in-plane magnetic field. In the second part of the project, we will design and prepare a system ofordered magnetic nanoelements in the vortex state set by an in-plane magnetic field. Such ordered nanoelementscan be considered as a single unit cell of the magnonic crystal. They can be also periodically arranged into afinite 2D array of interacting magnetic objects to observe the unidirectional spin waves. Therefore, ourinvestigation will be an important step towards the first experimental demonstration of topological magnons. |
Duration: | 1.1.2022 – 31.12.2024 |
TMD2DCOR – Metalické 2D dichalkogenidy prechodných kovov: príprava, štúdium vlastností a korelované stavy | |
Fabrication, physics and correlated states in metallic 2D transition metal dichalcogenides | |
Program: | SRDA |
Project leader: | Dr. rer. nat. Hulman Martin |
Annotation: | The discovery of graphene in 2004 has brought a massive interest of scientists active in condensed-matter physicson research of 2D materials. Even though these materials have a long history starting already in the twenties of the20th century, the past years have seen an intensive renascence of interest in 2D materials. Ultra-thin samples ofmany 2D materials have been successfully prepared with electronic properties that may exhibit correlatedelectronic phenomena such as charge density waves and superconductivity. One of the well-studied families of the2D materials are transition metal dichalcogenides (TMDs). TMDs consist of hexagonal layers of metal atomssandwiched between two layers of chalcogen atoms with a MX2 stoichiometry.In this project, we focus on those materials from the TMD family that exhibit strongly correlated electronic states:NbSe2, TiSe2, TaS2, TaSe2 and PtSe2. The goal of the project is to prepare ultrathin (≤ 10 nm) layers and bulksamples and characterise them thoroughly in terms of the thickness, crystallinity, homogeneity, optical andelectronic properties. A special attention will be paid to charge density wave states and superconductivity in thesematerials and how they evolve with the sample thickness, doping, external electric and magnetic fields and detailsof the growth process.The scientific program also aims at preparing heterostructures built up of these materials as well as hybrid systemscombining TMDs with other materials. This research also includes a detailed characterisation of heterostructures toprovide a feedback to optimise the growth process. |
Duration: | 1.7.2020 – 30.6.2023 |
Robustné spinové vlny pre budúce magnonické aplikácie | |
Robust spin waves for future magnonic applications | |
Program: | SRDA |
Project leader: | Dr. Mruczkiewicz Michal |
Annotation: | In this project we will focus on the theoretical and experimental investigation of spin wave dynamics at nanoscale. Spin wave is considered as candidate for an information carrier in ultrafast and energy efficient information processing devices. It is due the unique properties of spin waves, namely low heat dissipation, possible manipulation at nanoscale or reconfigurability. We are going to investigate specific spin wave systems, that can host robust, unidirectional and reprogrammable spin waves. Therefore, the results of this project will contribute to the field of modern magnetism, magnonics. |
Duration: | 1.7.2020 – 30.6.2023 |
Rast a charakterizácia materiálu zo skupiny dichalkogenidov prechodových kovov: diselenid titánu | |
Growth and characterization of a material from the group of transition metal dichalcogenides: titanium diselenide | |
Program: | VEGA |
Project leader: | Ing. Precner Marián, PhD. |
Duration: | 1.1.2019 – 31.12.2021 |