Collection articles
The Collection contains relevant articles from Nature Publishing Group.
Letters to the Editor
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The effect of magnetisation on the nature of light emitted by a substance
Journal:Nature 55, 347 (1897)
The last experiment performed by Michael Faraday was an unsuccessful attempt to observe the influence of a magnetic field on the spectral lines of sodium. More than 30 years later, Pieter Zeeman took up the challenge and observed a broadening of the lines, which was soon recognized to be the splitting that we know as the Zeeman effect. Zeeman's account of the discovery, translated for Nature from the Proceedings of the Physical Society of Berlin, includes an interpretation based on Hendrik Lorentz's idea of "small molecular elements charged with electricity", and a rough calculation of the charge to mass ratio of these "ions".
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Letter
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Image formation by induced local interactions: examples employing nuclear magnetic resonance
Journal:Nature 242, 190-191 (1973)
In 1973, Paul Lauterbur described an imaging technique that removed the usual resolution limits due to the wavelength of the imaging field. He used two fields: one interacting with the object under investigation, the other restricting this interaction to a small region. Rotation of the fields relative to the object produces a series of one-dimensional projections of the interacting regions, from which two- or three-dimensional images of their spatial distribution can be reconstructed. Application of this technique as magnetic resonance imaging is now widespread.
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History
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The way to NMR structures of proteins
Journal:Nature Structural Biology 8, 923-925 (2001); doi:10.1038/nsb1101-923
In 1998 Kurt Wüthrich was awarded the Kyoto Prize in Advanced Technology for having "developed a method of determining the conformations of proteins, nucleic acids and other biomacromolecules in solutions or biomembranes, where they exhibit their function". Wüthrich has used nuclear magnetic resonance (NMR) techniques to study proteins and nucleic acids since 1967. In a series of four papers his group outlined a framework for NMR structure determination of proteins in 1982, and in 1984 the first de novo structure of a globular protein in solution was determined. The Wüthrich group went on to solve more than 60 protein structures in solution, including the Antennapedia homeodomain, the cyclophillin A-cyclosporin A complex, and the human and bovine prion proteins. What follows is a personal recollection by Kurt Wüthrich of how he and his associates arrived at the first view of a protein structure through the NMR eye.
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Review
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Challenges for semiconductor spintronics
Journal:Nature Physics 3, 153-159 (2007); doi:10.1038/nphys551
High-volume information-processing and communications devices are at present based on semiconductor devices, whereas information-storage devices rely on multilayers of magnetic metals and insulators. Switching within information-processing devices is performed by the controlled motion of small pools of charge, whereas in the magnetic storage devices information storage and retrieval is performed by reorienting magnetic domains (although charge motion is often used for the final stage of readout). Semiconductor spintronics offers a possible direction towards the development of hybrid devices that could perform all three of these operations, logic, communications and storage, within the same materials technology. By taking advantage of spin coherence it also may sidestep some limitations on information manipulation previously thought to be fundamental. This article focuses on advances towards these goals in the past decade, during which experimental progress has been extraordinary.
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Review
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The emergence of spin electronics in data storage
Journal:Nature Materials 6, 813-823 (2007); doi:10.1038/nmat2024
Electrons have a charge and a spin, but until recently these were considered separately. In classical electronics, charges are moved by electric fields to transmit information and are stored in a capacitor to save it. In magnetic recording, magnetic fields have been used to read or write the information stored on the magnetization, which 'measures' the local orientation of spins in ferromagnets. The picture started to change in 1988, when the discovery of giant magnetoresistance opened the way to efficient control of charge transport through magnetization. The recent expansion of hard-disk recording owes much to this development. We are starting to see a new paradigm where magnetization dynamics and charge currents act on each other in nanostructured artificial materials. Ultimately, 'spin currents' could even replace charge currents for the transfer and treatment of information, allowing faster, low-energy operations: spin electronics is on its way.
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