Institution
University of Hamburg
Education•Hamburg, Germany•
About: University of Hamburg is a education organization based out in Hamburg, Germany. It is known for research contribution in the topics: Population & Laser. The organization has 45564 authors who have published 89286 publications receiving 2850161 citations. The organization is also known as: Hamburg University.
Papers published on a yearly basis
Papers
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TL;DR: Two-dimensional oriented attachment of lead sulfide nanocrystals into ultrathin single-crystal sheets with dimensions on the micrometer scale is reported, found that this process is initiated by cosolvents, which alter nucleation and growth rates during the primary nanocrystal formation, and is finally driven by dense packing of oleic acid ligands on {100} facets of PbS.
Abstract: Controlling anisotropy is a key concept in the generation of complex functionality in advanced materials. For this concept, oriented attachment of nanocrystal building blocks, a self-assembly of particles into larger single-crystalline objects, is one of the most promising approaches in nanotechnology. We report here the two-dimensional oriented attachment of lead sulfide (PbS) nanocrystals into ultrathin single-crystal sheets with dimensions on the micrometer scale. We found that this process is initiated by cosolvents, which alter nucleation and growth rates during the primary nanocrystal formation, and is finally driven by dense packing of oleic acid ligands on {100} facets of PbS. The obtained nanosheets can be readily integrated in a photodetector device without further treatment.
753 citations
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TL;DR: A review of new developments in theoretical and experimental electronic-structure investigations of half-metallic ferromagnets (HMFs) is presented in this article, where the effects of electron-magnon interaction in HMFs and their manifestations in magnetic, spectral, thermodynamic, and transport properties are considered.
Abstract: A review of new developments in theoretical and experimental electronic-structure investigations of half-metallic ferromagnets (HMFs) is presented. Being semiconductors for one spin projection and metals for another, these substances are promising magnetic materials for applications in spintronics (i.e., spin-dependent electronics). Classification of HMFs by the peculiarities of their electronic structure and chemical bonding is discussed. The effects of electron-magnon interaction in HMFs and their manifestations in magnetic, spectral, thermodynamic, and transport properties are considered. Special attention is paid to the appearance of nonquasiparticle states in the energy gap, which provide an instructive example of essentially many-body features in the electronic structure. State-of-the-art electronic calculations for correlated d-systems are discussed, and results for specific HMFs (Heusler alloys, zinc-blende structure compounds, CrO2, and Fe3O4) are reviewed.
748 citations
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University of Freiburg1, University of Trento2, University of Tübingen3, Graz University of Technology4, University of California, San Diego5, École Polytechnique Fédérale de Lausanne6, Imperial College London7, University of Washington8, University of Hamburg9, University of Arkansas for Medical Sciences10, Institute of Science and Technology Austria11, Technical University of Berlin12, University College London13
TL;DR: The BCI competition IV stands in the tradition of prior BCI competitions that aim to provide high quality neuroscientific data for open access to the scientific community and it is the hope that winning entries may enhance the analysis methods of future BCIs.
Abstract: The BCI competition IV stands in the tradition of prior BCI competitions that aim to provide high quality neuroscientific data for open access to the scientific community. As experienced already in prior competitions not only scientists from the narrow field of BCI compete, but scholars with a broad variety of backgrounds and nationalities. They include high specialists as well as students. The goals of all BCI competitions have always been to challenge with respect to novel paradigms and complex data. We report on the following challenges: (1) asynchronous data, (2) synthetic, (3) multi-class continuous data, (4) session-to-session transfer, (5) directionally modulated MEG, (6) finger movements recorded by ECoG. As after past competitions, our hope is that winning entries may enhance the analysis methods of future BCIs.
747 citations
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TL;DR: In this article, the Dzyaloshinskii-Moriya interaction was shown to lead to a left-rotating spin cycloid in a single atomic layer of manganese on a tungsten substrate.
Abstract: Chirality is a fascinating phenomenon that can manifest itself in subtle ways, for example in biochemistry (in the observed single-handedness of biomolecules) and in particle physics (in the charge-parity violation of electroweak interactions). In condensed matter, magnetic materials can also display single-handed, or homochiral, spin structures. This may be caused by the Dzyaloshinskii-Moriya interaction, which arises from spin-orbit scattering of electrons in an inversion-asymmetric crystal field. This effect is typically irrelevant in bulk metals as their crystals are inversion symmetric. However, low-dimensional systems lack structural inversion symmetry, so that homochiral spin structures may occur. Here we report the observation of magnetic order of a specific chirality in a single atomic layer of manganese on a tungsten (110) substrate. Spin-polarized scanning tunnelling microscopy reveals that adjacent spins are not perfectly antiferromagnetic but slightly canted, resulting in a spin spiral structure with a period of about 12 nm. We show by quantitative theory that this chiral order is caused by the Dzyaloshinskii-Moriya interaction and leads to a left-rotating spin cycloid. Our findings confirm the significance of this interaction for magnets in reduced dimensions. Chirality in nanoscale magnets may play a crucial role in spintronic devices, where the spin rather than the charge of an electron is used for data transmission and manipulation. For instance, a spin-polarized current flowing through chiral magnetic structures will exert a spin-torque on the magnetic structure, causing a variety of excitations or manipulations of the magnetization and giving rise to microwave emission, magnetization switching, or magnetic motors.
747 citations
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TL;DR: This article shows how every algorithm that uses a suffix tree as data structure can systematically be replaced with an algorithm that use an enhanced suffix array and solves the same problem in the same time complexity.
746 citations
Authors
Showing all 46072 results
Name | H-index | Papers | Citations |
---|---|---|---|
Rudolf Jaenisch | 206 | 606 | 178436 |
Bruce M. Psaty | 181 | 1205 | 138244 |
Stefan Schreiber | 178 | 1233 | 138528 |
Chris Sander | 178 | 713 | 233287 |
Dennis J. Selkoe | 177 | 607 | 145825 |
Daniel R. Weinberger | 177 | 879 | 128450 |
Ramachandran S. Vasan | 172 | 1100 | 138108 |
Bradley Cox | 169 | 2150 | 156200 |
Anders Björklund | 165 | 769 | 84268 |
J. S. Lange | 160 | 2083 | 145919 |
Hannes Jung | 159 | 2069 | 125069 |
Andrew D. Hamilton | 151 | 1334 | 105439 |
Jongmin Lee | 150 | 2257 | 134772 |
Teresa Lenz | 150 | 1718 | 114725 |
Stefanie Dimmeler | 147 | 574 | 81658 |