12 Apr 2017 |
Synchronization Effects in the Quantum World
Jülich, 12 March 2017 – A German–Italian team of researchers headed by the Jülich physicist Dirk Witthaut was able to verify a direct link between classical synchronization and quantum entanglement. The scientists examined a certain type of coupled quantum systems which can be implemented in experiments using Bose–Einstein condensates. They combined the classical theory of synchronization with simulations of quantum dynamics – and were able to show that classical synchronization predicts the development of entangled quantum states.
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Classical synchronization indicates persistent entanglement in isolated quantum systems, Dirk Witthaut, Sandro Wimberger, Raffaella Burioni, Marc Timme
Nature Communications, published 12 April, DOI: 10.1038/NCOMMS14829
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10 Apr 2017 |
A New View on the Origin of Magnetism
Jülich, 10 April 2017 – How does a ferromagnet behave during the transition to a paramagnetic state? The answer to this question is decisive for understanding the quantum-mechanical origins of magnetism – and may even point to a way to achieve faster data storage. With the aid of a novel measuring technique, a team of German and American researchers has succeeded in finding a new answer to this question.
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Band structure evolution during the ultrafast ferromagnetic-paramagnetic phase transition in cobalt, by Steffen Eich, Moritz Plötzing, Markus Rollinger, Sebastian Emmerich, Roman Adam, Cong Chen, Henry Cornelius Kapteyn, Margaret M. Murnane, Lukasz Plucinski, Daniel Steil, Benjamin Stadtmüller, Mirko Cinchetti, Martin Aeschlimann, Claus M. Schneider, Stefan Mathias, Science Advances, DOI: 10.1126/sciadv.1602094
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20 Mar 2017 |
Quantum Computers: New Basis Discovered for Stable Quantum Bits with Exotic Majorana Particles
Jülich, 21 March 2017 – Majorana particles are considered to be promising candidates for stable quantum bits. Their realization is one of the biggest challenges in the development of quantum computers. Almost 80 years ago, the Italian physicist Ettore Majorana predicted particles which are simultaneously their own antiparticles. However, only in the past few years has it been possible to experimentally approximate the existence of such Majoranas. Scientists from Forschungszentrum Jülich have now successfully performed an experiment which represents an important step towards creating Majoranas so that they can also be used for processing and storing quantum information. In collaboration with scientists from the universities of Würzburg and Duisburg-Essen, they found evidence in semiconductor nanowires for a new kind of coupling mechanism and extremely strong spin-orbit coupling. The latter is considered to be an important prerequisite for creating quantum bits in nanowires with the aid of these exotic particles.
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Signatures of interaction-induced helical gaps in nanowire quantum point contacts
S. Heedt, N. Traverso Ziani, F. Crépin, W. Prost, St. Trellenkamp, J. Schubert, D. Grützmacher, B. Trauzettel, Th. Schäpers
Nature Physics (published online 20 March 2017), DOI: 10.1038/NPHYS4070
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10 Jan 2017 |
New Hybrid Material for Future Spin Transistors
Jülich, 10 January 2017 – Spin-based transistors may replace conventional transistors in future since they require considerably less energy, however their industrial implementation has so far been hampered due to the lack of a suitable material. Early-career researcher Zeila Zanolli has now discovered a novel combination of graphene and barium manganese oxide which satisfies the conflicting requirements. Simulations conducted on the supercomputers at the Jülich Supercomputing Centre (JSC) have shown that the new hybrid material permits both precise spin orientation and good spin transport.
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Graphene-multiferroic interfaces for spintronics applications
Zeila Zanolli
Scientific Reports 6, Article number: 31346 (Published online: 23 August 2016)
doi:10.1038/srep31346
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20 Dec 2016 |
Characterization of Magnetic Nanovortices Simplified
Jülich, 20 December 2016 - Magnetic nanovortices, so-called “skyrmions”, count among the most promising candidates for the future of information technology. Processors and storage media making use of these tiny structures could one day lead to the further miniaturization of IT devices and improve their energy efficiency significantly. Materials possessing suitable vortices can be identified in particular by their topological charge, an essential characteristic of skyrmions. To determine this property experimentally has up to now been a very laborious process. Physicists from Jülich have now put forward a simpler method which could speed up the screening of suitable materials, using X-rays.
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Chirality-driven orbital magnetic moments as a new probe for topological magnetic structures;
Manuel dos Santos Dias et al; Nat. Commun. 7, 13613, DOI: 10.1038/ncomms13613
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16 Dec 2016 |
Einstein in an Iron Crystal
Jülich, 14 December 2016. Tiny relativistic effects form the basis of the functionalities in modern technology, as exemplified in magnetic hard disks and data storage media. Now for the first time, scientists have directly observed features in an electronic structure that could not be seen previously. Angle-resolved photoemission spectroscopy has enabled scientists from Forschungszentrum Jülich and LMU Munich to directly visualize the formation of shifts in the band structure (band gaps) of a sample of prototypical magnetic material as a response to the change in direction of a magnetic field. These gaps in the energy levels of electrons in the iron sample occur in keeping with Einstein’s theory of relativity, as electrons flowing through a crystal sample can “sense” the direction of the magnetic field.
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Fermi surface manipulation by external magnetic field demonstrated for a prototypical ferromagnet;
E. Mlynczak, M. Eschbach, S. Borek, J. Minár, J. Braun, I. Aguilera, G. Bihlmayer, S. Döring, M. Gehlmann, P. Gospodaric, S. Suga, L. Plucinski, S. Blügel, H. Ebert, and C. M. Schneider;
Phys. Rev. X 6, 041048 – Published 9 December 2016, DOI: 10.1103/PhysRevX.6.041048
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16 Dec 2016 |
Focused Interactions Important for Protein Dynamics
Jülich, 14 December 2016 - Many biological processes in cells function solely due to the phenomenon of diffusion. This ensures that particles are able to move randomly and aimlessly on the basis of their thermal energy alone. In this way, protein molecules get into close enough proximity to each other to, for example, carry out metabolic processes only achievable when acting together. A team of international researchers has now shown that weak attraction forces between proteins can enormously influence diffusion, if the protein molecules are as densely concentrated as under natural conditions in living cells.
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Dramatic influence of patchy attractions on short-time protein diffusion under crowded conditions;
Saskia Bucciarelli, Jin Suk Myung, Bela Farago, Shibananda Das, Gerard Vliegenthart, Olaf Holderer, Roland G. Winkler, Peter Schurtenberger, Gerhard Gompper, Anna Stradner;
Science Advances 2: e1601432 (2016); DOI: 10.1126/sciadv.1601432
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