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46:38 Foundation for Fundamental Research on Matter (FOM) English 2015

Entropy, information and order in soft matter

Entropy, information, and order are important concepts in many fields, relevant for materials to machines, for biology to econophysics. Entropy is typically associated with disorder; yet, the counterintuitive notion that a thermodynamic system of hard particles (colloids) might - due solely to entropy - spontaneously assemble from a fluid phase into an ordered crystal was first predicted in the mid-20th century. First demonstrated for rods, and then spheres, the ordering of colloids by entropy maximization upon crowding is now well established. In recent years, surprising discoveries of ordered entropic colloidal crystals of extraordinary structural complexity have been predicted by computer simulation and observed in the laboratory. These findings, presented in this talk, demonstrate that entropy alone can produce order and complexity beyond that previously imagined, and that, in situations where other interactions are also present, the role of entropy in producing order may be greatly underestimated. Glotzer discusses how new statistical mechanical principles learned from recent findings can be used to design shapes that promote long-range entropic order.
  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
1:06:47 Foundation for Fundamental Research on Matter (FOM) English 2015

Master class with David Awschalom

Eighty years since Dirac developed the quantum theory of electron spin, contemporary information technology still relies largely on classical electronics: the charge of electrons for computation and magnetic materials for permanent storage. There is a growing interest in exploiting spins in semiconductor nanostructures for the manipulation and storage of information in emergent technologies based upon spintronics and quantum logic. We provide an overview of temporally- and spatially-resolved optoelectronic measurements used to generate, manipulate, and interrogate electron and nuclear spin states in the solid state. In particular, we discuss progress toward scalable quantum systems based on quantum control and coherent coupling between single spins and optical photons for technologies beyond electronics. These demonstrations include advanced materials synthesis techniques, gigahertz-rate coherent manipulation, nondestructive single spin readout, nanofabrication of spin arrays, operation of a single nuclear spin quantum memory and recent material discoveries that represent progress toward the integration of spins and photons for future quantum information processing
  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
2:21:07 Foundation for Fundamental Research on Matter (FOM) English 2014

Master class with Andreas Heinrich

We all learn in quantum mechanics lectures how to treat the spin of an electron using the Pauli matrices of an S=1/2 system. However, the magnetic properties of atoms in gas and in particular those in a solid-state environment or in molecules are often much more complex and interesting. We will begin by trying to understand what happens when the spin of a quantum system is larger than S=1/2 at which point ligand fields (crystal fields in solids) become important and lead to important effects such as magnetic anisotropy. We will then move from the treatment of a single spin system to coupled spins. How do you set up spin matrices for such a situation and how do you find solutions to those problems? We will discuss some experimental findings about spin chains on surfaces as studied by STM. If time permits we will try to apply the concepts of coupled spin systems to quantum computation.
  • Published: 2014
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
47:58 Foundation for Fundamental Research on Matter (FOM) English 2014

Tuesday evening lecture with Andreas Heinrich

The scanning tunneling microscope has been an extremely successful experimental tool because of its atomic-scale spatial resolution. In recent years this has been combined with the use of low temperatures, culminating in precise atom manipulation and spectroscopy with microvolt energy resolution. In this talk I will review recent developments in investigating the electronic and magnetic properties of atoms and small clusters of atoms on surfaces. A large cluster of magnetic atoms behaves similar to a macroscopic magnetic particle: it's magnetization points along an easy-axis direction in space and magnetization reversal requires sufficient thermal energy to overcome a barrier. How many atoms does it take to create such a magnet? What are the properties of individual atoms on surfaces? Those are important questions for future technologies as well as for basic understanding of materials.
  • Published: 2014
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
39:52 Foundation for Fundamental Research on Matter (FOM) English 2014

Closing lecture with David Nelson

Population waves have played a crucial role in evolutionary history, as in the 'out of Africa' hypothesis for human ancestry. Population geneticists and physicists are now developing methods for understanding how mutations, number fluctuations and selective advantages play out in such situations. Once the behavior of pioneer organisms at frontiers is understood, genetic markers can be used to infer information about growth, ancestral population size and colonization pathways. Insights into the nature of competition and cooperation at frontiers are possible. Neutral mutations optimally positioned at the front of a growing population wave can increase their abundance by 'surfing' on the population wave. In addition, obstacles such as lakes, deserts and mountains alter migration fronts and organism geneologies in important and interesting ways, which can be illuminated by a kind of 'Huygens Principle' for biological waves. Experimental and theoretical studies of these effects will be presented, using bacteria and yeast as model systems.
  • Published: 2014
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
07:01 Foundation for Fundamental Research on Matter (FOM) English 2014

The Poster Prize ceremony at Physics@FOM Veldhoven 2014

Physics@FOM Veldhoven is a large congress that provides a topical overview of physics in the Netherlands. It is organised by the Foundation for Fundamental Research on Matter (FOM) and takes place each year in January. Traditionally, young researchers are given the chance to present themselves and their work alongside renowned names from the Dutch and international physics community. The programme covers Light and matter, Atomic, molecular and optical physics, Nanoscience and nanotechnology, Statistical physics and Soft condensed matter, Surfaces and interfaces, Physics of fluids, Subatomic physics, Plasma and fusion physics, and Strongly correlated systems. In 2014 there were about 400 poster presentations.
  • Published: 2014
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
2:17:42 Foundation for Fundamental Research on Matter (FOM) English 2015

Master class with Sharon Glotzer

Quasiperiodic crystals with long range rotational symmetry but no translational repeat unit have been known in metallic alloys since they were first reported in 1984. Yet only in the past ten years have such complex structures been reported in soft materials, comprised of, e.g., polymers, macromolecules, nanoparticles and colloids. In nearly all of these soft matter systems, quasiperiodicity is entropically stabilized, and any interactions are essentially short range. Interestingly, despite the fact that most metallic quasicrystals exhibit icosahedral symmetry, no icosahedral quasicrystals have been reported for soft matter systems. Instead, primarily 12-fold rotational symmetries are found, with recent, occasional reports of 8-fold, 10-fold, 18-fold, and even 24-fold planar quasicrystals. In this talk, we discuss common features and unifying principles for the self-assembly of soft matter quasicrystals, and we present results for the first icosahedral quasicrystal to be thermodynamically self-assembled in a computer simulation. This icosahedral quasicrystal is robust over a range of parameters, and is obtained from a single particle type interacting via a short-ranged, oscillatory pair potential that may be achievable in systems of colloidal spheres. The icosahedral quasicrystal we report is surrounded in parameter space by clathrates, important for deep sea methane storage, and other new crystal structures never before reported in a one-component system.
  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
2:35:42 Foundation for Fundamental Research on Matter (FOM) English 2014

Master class with Ursula Keller

There has been a long-standing, ongoing effort in the ultrafast laser field to reduce the pulse duration and increase the power to continue to empower existing and new applications. After 1990, new techniques such as semiconductor saturable absorber mirrors (SESAMs) and Kerr lens mode locking (KLM) allowed for the generation of stable pulse trains from diode-pumped solid-state lasers for the first time, and enabled the performance of such lasers to improve by several orders of magnitude with regards to pulse duration, pulse energy and pulse repetition rates. This master course will give an introduction to some key topics such as passive modelocking based on SESAMs, KLM, and soliton modelocking; frequency comb generation and parameters such as carrier envelope offset frequency and pulse repetition rate; and some selected topics in attosecond science.
  • Published: 2014
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
52:28 Foundation for Fundamental Research on Matter (FOM) English 2014

Opening lecture with Ursula Keller

Novel time-resolved attosecond streaking techniques are currently being applied in an attempt to answer a very fundamental questions in quantum mechanics, such as how fast can light remove a bound electron from an atom or a solid? Furthermore, the question of how long a tunneling particle spends inside the barrier has remained unresolved since the early days of quantum mechanics. The main theoretical contenders, such as the Buttiker-Landauer, the Eisenbud-Wigner (also known as Wigner-Smith), and the Larmor time give different answers. Yet recent attempts at reconstructing valence electron dynamics in atoms and molecules have entered a regime where the tunneling time genuinely matters. We used the attoclock technique to measure the tunneling delay time in strong laser field ionization of helium and reveal a real and not instantaneous tunneling time. The matching theoretical model predicts a strong implications on the investigation of electron dynamics in attosecond science, because a significant delay must be taken into account about when the electron hole dynamics begin to evolve.
  • Published: 2014
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
25:13 Foundation for Fundamental Research on Matter (FOM) English 2015

The FOM Prizes ceremony at Physics@FOM Veldhoven 2015

Physics@FOM Veldhoven is a large congress that provides a topical overview of physics in the Netherlands. It is organised by the Foundation for Fundamental Research on Matter (FOM) and takes place each year in January. Traditionally, young researchers are given the chance to present themselves and their work alongside renowned names from the Dutch and international physics community. The programme covers Light and matter, Atomic, molecular and optical physics, Nanoscience and nanotechnology, Statistical physics and Soft condensed matter, Surfaces and interfaces, Physics of fluids, Subatomic physics, Plasma and fusion physics, and Strongly correlated systems.
  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
2:16:47 Foundation for Fundamental Research on Matter (FOM) English 2015

Master class with Heinrich Jaeger

Granular materials are large amorphous aggregates of discrete, individually solid particles. Despite seemingly simple ingredients, such aggregates exhibit a wide range of complex behaviours that defy categorization as ordinary solids or liquids. This includes non-Newtonian flow behaviour and collective 'jamming' transitions. One of the key issues has long been how to link particle-level properties in a predictive manner to the behaviour of the aggregate as a whole. However, for actually designing a granular material, an inverse problem needs to be solved: for a given desired overall response, the task becomes finding the appropriate particle-level properties. This master class discusses new approaches to tackle the inverse problem by bringing concepts from artificial evolution to materials design. These results have general applicability and open up wide-ranging opportunities for materials optimization and discovery.
  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
2:15:19 Foundation for Fundamental Research on Matter (FOM) English 2014

Master class with David Nelson

Important ideas about mutations, genetic drift (survival of the luckiest) and natural selection (survival of the fittest), originally developed in population genetics, will be reviewed in a form suitable for physicists, with the aim of understanding the growth of bacterial or yeast colonies in a laboratory environment. When migrations of one- and two-dimensional populations are considered, results for mutation, selection and genetic drift are closely related to 'voter models' of interest in nonequilibrium statistical mechanics, suitably extended to allow for inflation of a thin layer of actively growing pioneers at the frontier of a colony of microorganisms undergoing a radial range expansions on a Petri dish.
  • Published: 2014
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
2:20:36 Foundation for Fundamental Research on Matter (FOM) English 2015

Master class with Alan Guth

Inflationary cosmology gives a very plausible explanation for many features of our universe, including its uniformity, itsmass density, and the patterns of the ripples that are observed in the cosmic microwave background. Most versions of inflation, however, imply that ouruniverse is not unique, but is part of a possibly infinite multiverse. The speaker will talk about how inflation works, and why he believes that the possibility of a multiverse should be taken seriously.
  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
2:12:34 Foundation for Fundamental Research on Matter (FOM) English 2014

Master class with Francis Halzen

Neutrino astronomy has reached a watershed with the construction and commissioning of the cubic-kilometer IceCube neutrino detector and its low energy extension DeepCore. The instrument detects neutrinos over a wide energy range: from 10 GeV atmospheric neutrinos to 1010 GeV cosmogenic neutrinos.Topics for discussion are: the scientific rational for building a kilometer-scale neutrino detector, the challenges in building IceCube and the present detector performance, initial results based on the more than 300,000 neutrino events recorded during construction. We will emphasize the measurement of the high-energy atmospheric neutrino spectrum extending to PeV energy and discuss IceCube's potential for neutrino physics and for identifying the particle nature of dark matter. Furthermore, we discuss the search for the still enigmatic sources of the galactic and extragalactic cosmic rays. Finally, we will discuss how the first data taken with the completed detector have revealed strong evidence for a flux of extraterrestrial neutrinos.
  • Published: 2014
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
1:04:50 Foundation for Fundamental Research on Matter (FOM) English 2015

Inflationary Cosmology: Is Our Universe Part of a Multiverse?

  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
09:32 Foundation for Fundamental Research on Matter (FOM) English 2015

The Poster Prize ceremony at Physics@FOM Veldhoven 2015

Physics@FOM Veldhoven is a large congress that provides a topical overview of physics in the Netherlands. It is organised by the Foundation for Fundamental Research on Matter (FOM) and takes place each year in January. Traditionally, young researchers are given the chance to present themselves and their work alongside renowned names from the Dutch and international physics community. The programme covers Light and matter, Atomic, molecular and optical physics, Nanoscience and nanotechnology, Statistical physics and Soft condensed matter, Surfaces and interfaces, Physics of fluids, Subatomic physics, Plasma and fusion physics, and Strongly correlated systems.
  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
53:33 Foundation for Fundamental Research on Matter (FOM) English 2015

Abandoning perfection for quantum technologies

Our technological preference for perfection can only lead us so far: as traditional transistor-based electronics rapidly approach the atomic scale, small amounts of disorder begin to have outsized negative effects. Surprisingly, one of the most promising pathways out of this conundrum may emerge from recent efforts to embrace defects and construct 'quantum machines' to enable new information technologies based on the quantum nature of the electron. Recently, individual defects in diamond and other materials have attracted interest as they possess an electronic spin state that can be employed as a solid state quantum bit at and above room temperature. Research at the frontiers of this field includes creating and manipulating these unusual states in a new generation of nanometer-scale structures. These developments have launched technological efforts aimed at developing applications ranging from secure data encryption to radical improvements in computation speed and complexity. This lecture will describe recent advances towards these goals, including the surprising ability to control atomic-scale spins for communication and computation within materials surrounding us for generations.
  • Published: 2015
  • Publisher: Foundation for Fundamental Research on Matter (FOM)
  • Language: English
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