Atoms

  • A Memory Effect at Single-Atom Level

    The energy behavior of the giant atom shows a memory. Lingzhen Guo/Max Planck Institute for the Science of Light

    An international research group has observed new quantum properties on an artificial giant atom and has now published its results in the high-ranking journal Nature Physics. The quantum system under investigation apparently has a memory - a new finding that could be used to build a quantum computer. The research group, consisting of German, Swedish and Indian scientists, has investigated an artificial quantum system and found new properties. The experiments were done at Chalmers University of technology (Sweden) and the theory was done by Dr. Lingzhen Guo at Max Planck Institute for the Science of Light (MPL) in Erlangen. The measured effect has never been observed on a single quantum system.

  • A Nano-Roundabout for Light

    Functional principle of a nano-roundabout.  © TU Wien

    At TU Wien, it was possible to create a nanoscale optical element that regulates the flow of light particles at the intersection of two glass fibers like a roundabout. A single atom was used to control the light paths. Just like in normal road traffic, crossings are indispensable in optical signal processing. In order to avoid collisions, a clear traffic rule is required. A new method has now been developed at TU Wien to provide such a rule for light signals. For this purpose, the two glass fibers were coupled at their intersection point to an optical resonator, in which the light circulates and behaves as in a roundabout. The direction of circulation is defined by a single atom coupled to the resonator. The atom also ensures that the light always leaves the roundabout at the next exit. This rule is still valid even if the light consists merely of individual photons. Such a roundabout will consequently be installed in integrated optical chips – an important step for optical signal processing.

  • An Atomic Quantum Bit Made Switchable

    Depending on the orientation of an applied magnetic field, quantum tunneling of the magnetisation allows to either freeze or to flip magnetic moments. © University of Augsburg/IfP/EKM

    One bit per atom: Augsburg-based physicists and US colleagues are reaching the ultimate limit for nanoscale data storage

  • Attoseconds Break into Atomic Interior

    After the interaction of a xenon atom with two photons from an attosecond pulse (purple), the atom is ionized and multiple electrons (green balls) are ejected. This two-photon interaction is made possible by the latest achievements in attosecond technology. Graphic: Christian Hackenberger

    A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

  • Breaking Newton's Law

    Physicists have observed an intriguing oscillatory back-and-forth motion of a quantum particle in a one-dimensional atomic gas. Florian Meinert

    In the quantum world, our intuition for moving objects is strongly challenged and may sometimes even completely fail. Experimental physicists of the University of Innsbruck in collaboration with theorists from Munich, Paris and Cambridge have found a quantum particle which shows an intriguing oscillatory back-and-forth motion in a one-dimensional atomic gas. A ripe apple falling from a tree has inspired Sir Isaac Newton to formulate a theory that describes the motion of objects subject to a force. Newton’s equations of motion tell us that a moving body keeps on moving on a straight line unless any disturbing force may change its path. The impact of Newton’s laws is ubiquitous in our everyday experience, ranging from a skydiver falling in the earth's gravitational field, over the inertia one feels in an accelerating airplane, to the earth orbiting around the sun.

  • Breakthrough with a chain of gold atoms

    Arists’ view of the quantized thermal conductance of an atomically thin gold contact. Created by Enrique Sahagun

    In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport. The precise control of electron transport in microelectronics makes complex logic circuits possible that are in daily use in smartphones and laptops. Heat transport is of similar fundamental importance and its control is for instance necessary to efficiently cool the ever smaller chips. An international team including theoretical physicists from Konstanz, Junior Professor Fabian Pauly and Professor Peter Nielaba and their staff, has achieved a real breakthrough in better understanding heat transport at the nanoscale.

  • Chemists connect three components with new coupling reaction

    The new reaction, explained using plastic building bricks: In a single reaction, three (bottom) instead of two (top right) chemical components are linked via carbon-carbon bonds. Photo: WWU/Ludger Tebben

    In the current issue of the "Science" magazine, a team of chemists led by Prof. Armido Studer from the Institute of Organic Chemistry at Münster University present a new approach which enables three – and not, as previously, two – chemical components to be "coupled" in one single reaction without any transition metal.

    In the current issue of the "Science" magazine, chemists at Münster University present a new approach which for the first time enables three – and not, as previously, two – chemical components to be "coupled" in one single reaction, without any metals to aid the process. The researchers succeeded in producing not only pharmaceutically relevant compounds containing fluorine, but also various γ-lactones. These organic compounds occur widely in various types of fruit and also, for example, as flavouring substances in whisky and cognac.

  • DFG Funding: An Atom Trap for Water Dating

    Atom trap wherein 39Ar atoms are captured and detected. Florian Freundt, Institute of Environmental Physics, Heidelberg University

    A Heidelberg physics project funded by the German Research Foundation (DFG) will focus on a new type of dating method for use in the earth and environmental sciences. The research team will deploy a special radioactive isotope of the noble gas argon (Ar) for the purpose of water dating. This isotope is useful for determining age in the range of 50 to 1,000 years. Prof. Dr Markus Oberthaler of the Kirchhoff Institute for Physics and Prof. Dr Werner Aeschbach of the Institute of Environmental Physics of Heidelberg University will direct the three-year project.

  • Direct Coupling of the Higgs Boson to the Top Quark Observed

    CMS detector in a cavern 100 m underground at CERN’s Large Hadron Collider. CERN

    An observation made by the CMS experiment at CERN unambiguously demonstrates the interaction of the Higgs boson and top quarks, which are the heaviest known subatomic particles. This major milestone is an important step forward in our understanding of the origins of mass. Physicists at the University of Zurich made central contributions by incorporating sophisticated data analysis methods that allowed this benchmark to be reached much earlier than expected.

  • Electron highway inside crystal

    Step edges on topological crystalline insulators may lead to electrically conducting pathways where electrons with opposite spin spin move in converse directions - any U-turn is prohibited. Picture: Thomas Bathon/Paolo Sessi/Matthias Bode

    Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science. Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was highlighted again as the Royal Swedish Academy of Sciences in Stockholm awarded this year's Nobel Prize in Physics to three British scientists for their research of so-called topological phase transitions and topological phases of matter.

  • Extremely Hard yet Metallically Conductive: Bayreuth Researchers Develop Novel Material with High-tech Prospects

    The structure of rhenium nitride pernitride containing single nitrogen atoms (red) and N-N nitrogen dumbbells (blue). Larger balls show rhenium atoms. Illustration: Maxim Bykov. Illustration: Maxim Bykov.

    An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".

  • How photons change chemistry

    Photons in an optical cavity alter the properties of molecules, such as their binding length. Jörg M. Harms/MPSD

    The quantum nature of light does usually not play an important role when considering the chemical properties of atoms or moelcules. In an article published in the Proceedings of the National Academy of Sciences scientists from the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron-Laser Science (CFEL) in Hamburg show, however, that under certain conditions photons can strongly influence chemistry. These results indicate the possibility that chemical processes can be tailored by photons.

  • Ideal Size for Computer Memory

    Atomic-scale computer simulation of a CBRAM cell subjected to 1mV voltage: electron trajectories (blue and red lines); copper atoms (grey); silicon and oxygen atoms (orange). © Mathieu Luisier / ETH Zurich

    Ultraprecise simulation of a computer storage technology known as CBRAM reveals its optimal geometry: an insulator roughly ten atoms thick sandwiched between two electrodes. CBRAM (conductive bridging random access memory) could play a fundamental role in memory in the future by storing data in a non-volatile (i.e., near-permanent) way. To reduce the size and power consumption of such components, it is essential to precisely understand their behaviour at the atomic level. 

  • Individual Impurity Atoms Detectable in Graphene

    Using the atomic force microscope’s carbon monoxide functionalized tip (red/silver), the forces between the tip and the various atoms in the graphene ribbon can be measured. Image: University of Basel, Department of Physics

    A team including physicists from the University of Basel has succeeded in using atomic force microscopy to clearly obtain images of individual impurity atoms in graphene ribbons. Thanks to the forces measured in the graphene’s two-dimensional carbon lattice, they were able to identify boron and nitrogen for the first time, as the researchers report in the journal Science Advances.

  • Kaiserslautern physicists observe diffusion of individual atoms in light bath

    First author Farina Kindermann and Professor Artur Widera in front of a quantum gas experi-mental setup for investigations on single atoms. University of Kaiserslautern/Thomas Koziel

    In a combination of experiments and theory the diffusion of individual atoms in periodic systems was understood for the first time. The interaction of individual atoms with light at ultralow temperatures close to the absolute zero temperature point provides new insights into ergodicity, the basic assumption of thermodynamics. Quantum physicists at University of Kaiserslautern have published their results together with colleagues in the renowned scientific journal “Nature Physics”.

  • Light-driven atomic rotations excite magnetic waves

    Light-driven atomic rotations (spirals) induce coherent motion of the electronic spins (blue arrows). Image: J.M. Harms/MPI for the Structure and Dynamics of Matter

    Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion. Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how the ultrafast light-induced modulation of the atomic positions in a material can control its magnetization. An international research team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter at CFEL in Hamburg used terahertz light pulses to excite pairs of lattice vibrations in a magnetic crystal.

  • Matter-antimatter symmetry confirmed with precision record

    Sketch of the experimental setup used at CERN for the determination of the antiproton-to-electron mass ratio. Graphic: Masaki Hori

    CERN experiment sets precision record in the measurement of the antiproton to electron mass ratio using a new innovative cooling technique. According to the Standard Model of elementary particle physics, to each particle exists an antiparticle that is supposed to behave exactly the same way. Thus, “anti-people” in an “anti-world” would observe the same laws of physics, or make the same experiences in general, as we do. This postulate is, however, difficult to prove, since it is almost impossible to perform measurements on antimatter: whenever an antiparticle meets is matter-counterpart, both particles annihilate, accompanied by the creation of energy.

  • Measuring entropy on a single molecule

    Scanning Tunneling Microscope schematic

    A scanning-tunneling microscope (STM), used to study changes in the shape of a single molecule at the atomic scale, impacts the ability of that molecule to make these changes – the entropy of the molecule is changed and, in turn, can be measured. The study is published in Nature Communications. Chemical reactions, especially in biological systems, oftentimes involve macromolecules changing their shape – their “configuration” – for instance, by rotation or translational movements. To study what drives or impedes molecular mobility in more detail chemists and physicists turn to simplified model systems such as individual molecules adhering to a surface. These can then be investigated at temperatures just a few degrees above absolute zero (-273 degrees Celsius) using, for instance, a scanning tunneling microscope (STM), which can probe numerous physical properties of surfaces at the atomic level.

  • Molekül-Motoren mit Licht-Antrieb

    Bahnbrechende Entwicklung: Zwei Nano-Maschinen (weiß) auf einer 8x8 Nanometer großen Kupferoberfläche (grau), aufgenommen bei -267° mit einem Rastertunnelmikroskop. In Gelb die Molekül-Modelle der Maschinen. Foto: Uni Graz/Grill

    ForscherInnen der Uni Graz steuern Nano-Maschinen auf Oberflächen. Ferngesteuerte Nano-Maschinen, angetrieben von einem Lichtstrahl, reinigen Oberflächen, bringen spezielle Pharmazeutika im Körper an ihren Zielort oder bauen elektronische Strukturen aus einzelnen Atomen. Dieser Zukunftsvision ist die Arbeitsgruppe von Univ.-Prof. Dr. Leonhard Grill vom Institut für Chemie der Karl-Franzens-Universität Graz einen großen Schritt nähergekommen: Dem Team ist es gelungen, einzelne molekulare Maschinen durch Laserlicht gezielt auf einer Oberfläche zu bewegen und währenddessen zu beobachten. Die Ergebnisse der Studie werden in der nächsten Ausgabe des Magazins „ACS Nano“ publiziert und sind online bereits veröffentlicht.

  • More than Just Spectators

    Computer simulations of the motion across the surface of a metal suggest that in the presence of a layer of bromide ions (magenta) sulphur atoms (yellow) change their positions by dipping into it. Copyright: Deuchler

    Physics team at Kiel University investigates influence of ions on atomic motions. In batteries, fuel cells or technical coatings, central chemical processes take place on the surface of electrodes which are in contact with liquids. During these processes, atoms move over the surface, but how this exactly happens has hardly been researched. Physicists at Kiel University want to gain a better understanding of these motions, and the role of the chemical components involved. To do so, they observe with highest microscopic resolution how sulphur atoms move on copper electrodes, which are immersed in different saline solutions.