Nacházíte se

Události

Seminář / Pondělí, 19.11.2018 10:00

S. I. Tarapov (Usikov Institute of Radiophysics and Electronics NAS, Kharkov, Ukraine)

The technique and installation for Electron Spin Resonance (ESR) experiments at extra high frequencies f = 5–120 GHz, static magnetic fields up to H = 7 T and very low temperatures (up to T = 0.3 K) are presented. Analysis of experimental ESR/FMR research of some kind of magnetic structures (namely – Co-nanoelements, structured ferrites [1], manganite-perovskite structures [2], etc.) will be given. Besides, physical phenomena, which take place in magnets, possessing well-controlled ESR-features are under discussion. Namely, Sr-doped...

Seminář / Úterý, 20.11.2018 10:00

Rodolfo Miranda (1 IMDEA Nanociencia, Cantoblanco, 20760 Madrid, Spain; ‎2 Departamento de Física de la Materia Condensada, Instituto Nicolás Cabrera e IFIMAC, Universidad Autónoma de Madrid, Cantoblanco, 28760 Madrid, Spain)

Creating an ordered 2D array of objects with protected magnetic moments deposited at surfaces, individually addressable and with potentially controlled interactions between their spins would be highly desirable for different quantum technologies. Being able to visualize the distribution in space of the spins is crucial to advance our knowledge and control of these systems. Below a certain temperature, a magnetic moment located at the surface can be screened by the electron sea of the substrate giving rise to a many body state known as Kondo resonance.

We present some selected...

Seminář / Úterý, 20.11.2018 15:00

Peter Zalom (Department of Condensed Matter Theory, Czech Acad. of Sci.)

Abstract:  The Kondo effect is a strong correlation non-perturbative emergent phenomenon. It was first discovered in the bulk by analyzing magnetic impurities embedded in normal metal. With the progress of nanodevice fabrication a renewed interest in Kondo physics has been rekindled. To obtain reliable quantitative predictions for such experiments, unbiased numerical simulations such as various variants of quantum Monte Carlo (QMC), or numerical renormalization group (NRG) are widely used. On the other hand, analytic approaches are generally based on perturbative...

Seminář / Středa, 21.11.2018 15:00

Martin Friák (Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22,CZ-616 62 Brno, Czech Republic)

Abstract: Alloys consisting of multiple principal elements in approximately equiatomic concentrations have been termed high (configurational) entropy alloys (HEAs). They represent a very interesting class of materials since certain combinations of elements in a single phase may exhibit a number of unusual physical properties with high potential for applications. The first part of the talk will provide a representative example of HEAs, the equiatomic CrMnFeCoNi alloy, which we studied using both experimental and theoretical tools. In particular, we found that the material...

Seminář / Čtvrtek, 22.11.2018 13:00

Dr. Klaus Ellmer (Optotransmitter-Umweltschutz-Technologie e.V.)

    Magnetron sputtering, invented by the renowned plasma physicist Penning already in 1939, is since more than 30 years a widely used large-area, plasma-assisted deposition method for many industrial applications, mostly used in fields like architectural and low emissivity glass coatings, mirrors and absorbers for solar concentrators, magnetic films for hard disks or hard coatings for tools, i.e., mainly for metals, oxides and nitrides. In the rising thin film photovoltaics industry, magnetron sputtering is only used for the deposition of metallic back contacts (Ag, Mo)...

Seminář / Úterý, 27.11.2018 15:00

Jens Paaske (Niels Bohr Institute, University of Copenhagen)

Abstract: Apart from their potential for quantum computing, topological superconductors have instigated renewed interest in the intricate interplay between superconductivity and magnetic degrees of freedom. This question dates back to the 1950’ies, but the recent advances in material growth and custom made hybrid materials provide an exciting new perspective on this venerable problem. In this seminar, I will discuss a possible platform for frustrated magnetism utilizing a Cooper pair mediated long-ranged indirect exchange interaction in two-dimensional (2D) magnetic adatom...

Seminář / Středa, 28.11.2018 15:00

Jaromír Chalupský (Fyzikální ústav AV ČR)

V uplynulých letech došlo ve fyzice interakce rentgenového laserového záření s hmotou k nebývalému pokroku, za což vědecká komunita vděčí novým intenzivním zdrojům rentgenového záření. Rychlý vývoj na poli rentgenového laserování však klade stále větší požadavky na diagnostiku rentgenových fotonových svazků, jejichž parametry neustále rostou. Jednu z velkých výzev představuje přesná prostorová charakterizace fokusovaných laserových polí. V důsledku vysokých intenzit záření v ohniscích o velikosti okolo jednoho mikrometru jsou na diagnostické metody kladeny nároky vysoké radiační odolnosti...

Seminář / Úterý, 04.12.2018 10:00

J. Michael Gottfried (Department of Chemistry, University of Marburg, Germany)

The synthesis of carbon-based and heterocyclic nanostructures on surfaces has attracted considerable attention as a versatile approach for the functionalization of interfaces and the preparation of new materials. In this lecture, examples for the on-surface synthesis of novel conjugated hydrocarbon and nitrogen-doped materials, organometallic compounds, and metal complexes with cyclic and open-chain topology will be discussed. Unusual regioselectivity of C-C coupling reactions achieved by monoselective aromatic C-H bond activation will be explained on the basis of a detailed discussion of...

Seminář / Úterý, 11.12.2018 15:00

S. Khmelevskyi (Center for Computational Materials Science, Vienna University of Technology,Vienna, Austria.)

Abstract: The magnetic materials might be sub-divided into the three major classes that requires special approaches and has specific problems, but also allowing for specific simplifications. This classes are magnetic insulators, 4f-metals with high degree of the magnetic moment localizations and d-metals and intermetallic compounds and alloys. For the first classes an important role of the correlation effects are evident, but quantum Heisenberg model with some modifications provide robust description of the finite temperature magnetic properties. The class of the d-metallic...

Seminář / Středa, 12.12.2018 16:00

Ortwin Hess (Imperial College London)

Nanoplasmonics and Metamaterials have in the last 15 years inspired scientists to think about photonics beyond traditional constraints imposed by natural materials in which light propagates to conceive functionalities such as subwavelength imaging and broadband ultraslow light. While most concepts have initially been demonstrated at longer wavelengths and for microwaves, they have continuously moved to optical frequencies and beyond. Embracing nonlinearity and (quantum) gain [1], exciting phenomena such as ‘dark-light’ [2] and cavity-free [3] nano-lasing and room temperature single...