Dvořákovy přednášky


Vladimír Dvořák (1934–2007)

Významný český vědec, který pracoval ve fyzice pevných látek. Zabýval se teorií feroelektrických látek a strukturálních fázových přechodů. Celý svůj produktivní život spojil s Fyzikálním ústavem. Byl jeho ředitelem v letech 1993-2001. Členem Učené společnosti byl od r. 1995. Byl protagonistou revolučních reforem ve Fyzikálním ústavu po roce 1989. K uctění této osobnosti a jeho práce organizuje Fyzikální ústav každoročně slavnostní Dvořákovu přednášku, přednesenou mezinárodně uznávanou autoritou v některém z oborů výzkumu Fyzikálního ústavu.


Photovoltaics at Terawatt Scale – Science, Engineering and Technology in Energy Transition

The 13th Dvořák Lecture
Professor Marko Topič
University of Ljubljana, Slovenia

At global and European scales, electricity is the cornerstone of decarbonized modern energy systems. Solar, hydro and wind rank among key renewable energy sources to deliver electricity in sufficient quantities, at affordable cost, in a sustainable manner and reduce energy dependency on fossil fuel imports. They offer a world with a 100% renewable electricity supply where electricity is accessible to all and where electricity makes major inroads into satisfying final energy demand for living, including communications, transport, efficient heating, and even synthetic fuels.
Solar Photovoltaics (PV) thus play a prominent role to achieve the EU’s clean energy targets and climate change mitigation, as well as the global sustainability goals. Last year it exceeded one terawatt (1 TW = 1000 GW) of installed power globally and is entering the multi-terawatt era. Are we getting ready for the multi-TW scale PV and TW scale production per year?
We will review the ubiquitous availability of sunlight, the fascinating PV technology’s modularity and the continuous cost reductions that path a way solar PV to become the largest source of electricity worldwide. Although with already proven economical and environmental competitiveness on its journey to become a major player in the clean energy system, it must successfully address further challenges in science, engineering and technology, topics broadly encompassed under themes of performance enhancement and cost reduction, manufacturing processes, quality and circularity, integration and double use along with public support and socio-economic transition.
The latest R&D activities in silicon and perovskite photovoltaics globally will be presented with a contribution from the Laboratory of Photovoltaics and Optoelectronics (LPVO), which is the largest PV research group in Slovenia. An interplay of the whole optimization loop, from modeling and optoelectronic analysis to fabrication and advanced characterization of high-efficiency perovskite solar cells (PSC), will be explained. We will shed light on the stability of PSC under real conditions, development of measuring systems for monitoring the stability of perovskite single-junction and tandem solar cells, optical optimization of perovskite-silicon tandem solar cells and energy yield analysis of single junction and tandem PSCs.

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High power lasers: from intense x-ray beams to relativistic nanophotonics

The 12th Dvořák Lecture
Professor Jorge J. Rocca
Colorado State University, USA

Compact lasers operating at high repetition rates now achieve record powers and can operate at unprecedently short wavelengths. This lecture will review the development of compact plasma-based soft x-ray lasers that are enabling the realization of a variety of applications in nanoscience and nanotechnology on a table-top. Plasma-based x-ray lasers provide extremely monochromatic high energy pulses that can reach full coherence. They allow experiments such as single-shot nanoscale morphologic and composition imaging, error-free nano-patterning, and the study of the electronic structure and reactivity of nanoclusters, in compact facilities.

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Electric Field Control of Magnetism: From Global Markets to Spin Orbit Coupling

The 11th Dvořák Lecture
prof. Ramamoorthy Ramesh
Department of Physics and Department of Materials Science and Engineering, University of California, Berkeley, USA

The emergence of the “Internet of Things” and the explosion of Artificial Intelligence/Machine Learning applications are likely to push up significantly the market for microelectronics. The related energy consumption could increase by 20–25%. Thus, looking for a new generation of ultralow-power memories and switches is an area of significant current research. Perovskite oxides exhibit a rich spectrum of functional responses, including magnetism, ferroelectricity,...

Now available on YouTube

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Molecular Understanding, Design and Development of Ultra-Low Fouling Zwitterionic Materials

The 10th Dvořák Lecture
prof. Shaoyi Jiang
Department of Chemical Engineering, University of Washington, Seattle, USA

An important challenge in many applications, ranging from biosensors to drug delivery, is the prevention of nonspecific protein adsorption on surfaces. To address this challenge, our goals are twofold. First, we strive to provide a fundamental understanding of nonfouling mechanisms at the molecular level using an integrated experimental and simulation approach.

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Advanced scintillators for fast timing applications

The 9th Dvořák lecture
Prof. Paul Lecoq
CERN, Geneva, Switzerland

The future generation of radiation detectors is more and more demanding on timing performance for a wide range of applications, such as time of flight (TOF) techniques for PET cameras in medical imaging and particle identification in nuclear physics and high energy physics detectors, precise event time tagging in high luminosity accelerators and a number of photonic applications based on single photon detection.

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Gravitational-wave astrophysics

The 8th Dvořák Lecture
Prof. Marco Cavaglià
Department of Physics and Astronomy, University of Mississippi, USA

In 1916 Albert Einstein demonstrated that the theory of General Relativity allows for wave-like, space time perturbations propagating with the speed of light. Two years later, he calculated his famous quadrupole formula, describing how these “gravitational” waves can be generated. However, due to the extreme weakness of gravity, detecting gravitational waves seemed an impossible task. They even became a matter of controversy with Einstein himself becoming convinced they did not exist. It took several decades before the first attempts to detect gravitational waves started in the sixties with the pioneering work of Joseph Weber. Although the orbital decay of the PSR B1913+16 binary pulsar provided an indirect proof of the existence of gravitational waves, their direct detection remained nevertheless elusive. The long quest to detect gravitational waves finally ended on February 11, 2016, when scientists from the Laser Interferometer Gravitational-wave Observatory (LIGO) Scientific Collaboration and the Virgo Collaboration announced the first detection of a gravitational-wave signal from a merger of two stellar mass black holes.

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X-ray lasers and the challenges facing structural sciences

The 7th Dvořák Lecture
Prof. Janos Hajdu
Laboratory of Molecular Biophysics, Uppsala University, Sweden & the European XFEL GmbH, Hamburg, Germany

Theory predicts that with an ultra-short and extremely bright coherent X-ray pulse, a single diffraction pattern may be recorded from a large macromolecule, a virus, or a cell before the sample explodes and turns into a plasma. The over-sampled diffraction pattern permits phase retrieval and hence structure determination. X-ray lasers capable to deliver ultra bright and very short X-ray pulses for such experiments have recently started operations. Free-electron lasers are the most brilliant sources of X-rays to date, exceeding the peak brilliance of conventional synchrotrons by a factor of 10 billion, and improving. In the duration of a single flash, the beam focused to a micron-sized spot has the same power density as all the sunlight hitting the Earth, focused to a millimetre square. The interaction of an intense X-ray pulse with matter is profoundly different from that of an optical pulse. Our aim in biology is to step beyond conventional damage limits and develop the science and technology required to enable high-resolution imaging of biological objects. The talk will summarise imaging results from the Linac Coherent Light Source, including studies on live cyanobacteria.

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The LASER: a Historical Perspective

The 6th Dvořák Lecture
Orazio Svelto
Politecnico di Milano, Italy

From the race to make the first laser to early developments in laser science, a description will be made of the most important achievements. Likewise, the birth of nonlinear optics and the ad- vent of ultrafast laser science will also be considered. In any case, a very coarse review of some of the most important achievements will be presented, with the addition of a few anecdotes and curiosities as derived by the personal reminiscence of the author. So far, 21 scientists have been awarded the Nobel Prize for research- es on lasers or with lasers. A coarse review and some critical historical connection between these awards will also be considered.

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The long journey to the Higgs boson and beyond at the LHC

The 5th Dvořák Lecture
Peter Jenni
University of Freiburg, Germany and CERN, Geneva, Switzerland

Since three years the experiments at the Large Hadron Collider (LHC), in particular ATLAS, investigate particle physics at the highest collision energies ever achieved in a laboratory. Following a rich harvest of results for Standard Model (SM) Physics came in 2012 the first spectacular discovery of a new, heavy particle, most likely the long-awaited Higgs boson. The latest results with the full data set accumulated over the first three-years running period of the LHC will be presented. Other, far-reaching results can already be reported for exploratory new physics searches like Supersymmetry (SUSY) and its implication for Dark Matter in the Universe, Extra Dimensions, and the production of new heavy particles.

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Graphene Ten Years Later

The 4th Dvořák Lecture
Prof. Allan H. MacDonald
The University of Texas at Austin, USA

Graphene is an atomically two-dimensional material which was first isolated for electronic property studies by Novoselov, Geim and collaborators from the University of Manchester about ten years ago. It is a gapless semiconductor formed entirely from carbon atoms and can be viewed as a giant aromatic molecule. Graphene’s honeycomb lattice structure is bipartite; atoms on one sublattice have three nearest neighbours all on the other sublattice. Its conduction and valence band states are both formed from graphene π-bands and differ only in the phase difference between their sublattice projections. Because it is two-dimensional, its carrier density can be tuned over a broad range without introducing dopants.

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Superfluid Helium-3: From very low Temperatures to the Big Bang

The 3rd Dvořák Lecture
Prof. Dieter Vollhardt
University of Augsburg, Germany

Since their discovery in 1971 the superfluid phases of Helium-3 have proved to be the ideal testing ground for many fundamental concepts of modern physics. Phenomena such as Cooper pairing, macroscopic quantum coherence, spontaneous breaking of high symmetries, and the formation of exotic topological defects are not only an important enrichment of the physics of condensed matter, but also provide important links to particle physics, the structure of the early universe and, most recently, quantum turbulence. In my lecture I will present a simple introduction into the physics of superfluid Helium-3, and describe the progress made in this fascinating field of basic research.

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Quantum Information and the Foundations of Quantum Mechanics

The 2nd Dvořák Lecture
Prof. Anton Zeilinger
University of Vienna, Austria

Research on the foundations of quantum mechanics has given rise to the field of quantum information science. It should be stressed that this research beginning around the 1970s was not motivated by search for applications but rather by pure fundamental curiosity. Today, quantum computation, quantum teleportation, quantum communication, or quantum cryptography are novel concepts in information technology with no classical parallel. The resulting experimental development in quantum information science has renewed the debate about the foundations of quantum mechanics and it has led to unprecedented control of quantum systems. All this again opens up the door for novel fundamental experimental research directions. For example, the high-precision control of entangled photon states even over distances as large as those between the two Canary Islands of Tenerife and La Palma allows novel tests of the concepts of nonlocality and realism. Or, to mention another example, the development of quantum microoptics opens up new experiments in higher-dimensional Hilbert spaces. Such experiments in turn will again give rise to novel possibilities in quantum information science.

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Thermodynamic Approach to Nano-Inhomogeneous Ferroelectrics

The 1st Dvořák Lecture
Prof. Yoshihiro Ishibashi
Nagoya University, Japan

Collaboration with Vladimir Dvorak started when he stayed in Nagoya for three months in 1975, and lasted until his final days. His visit to Nagoya gave me big stimuli and benefits. I could learn how to apply the group theory to phase transitions directly from him, and since then we could jointly make a certain contribution to the progress of the theory of ferroelectric phase transitions. Among our joint works, the most memorable one is the development of the theory of the incommensurate phase transitions, of which much was not known at that time. This subject had been already discussed among us during his stay, but the first joint paper reporting results of research appeared in J. Phys. Soc. Japan in January 1978, more than two years after his return to Prague. I am now reminded fondly of great patience required in Prague and Nagoya in the days of air-mail communication at the best.

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