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A step nearer to understanding superconductivity
June 07, 2007Transporting energy without any loss, travelling in magnetically levitated trains, carrying out medical imaging (MRI) with small-scale equipment: all these things could come true if we had superconducting materials that worked at room temperature. Today, researchers at CNRS have taken another step forward on the road leading to this ultimate goal. They have revealed the metallic nature of a class of so-called critical high-temperature superconducting materials. This result, which was published in the 31 May 2007 issue of the journal Nature, has been eagerly awaited for 20 years. It paves the way to an understanding of this phenomenon and makes it possible to contemplate its complete theoretical description.
Superconductivity is a state of matter characterized by zero electrical resistance and impermeability to a magnetic field. For instance, it is already used in medical imaging (MRI devices), and could find spectacular applications in the transport and storage of electrical energy without loss, the development of transport systems based on magnetic levitation, wireless communication and even quantum computers. However, for now, such applications are limited by the fact that superconductivity only occurs at very low temperatures. In fact, it was only once a way of liquefying helium had been developed, which requires a temperature of 4.2 kelvins (-269 °C), that superconductivity was discovered, in 1911 (a discovery for which the Nobel Prize was awarded two years later.)
Since the end of the 1980s (Nobel Prize in 1987), researchers have managed to obtain 'high temperature' superconducting materials: some of these compounds can be made superconducting simply by using liquid nitrogen (77 K, or -196 °C). The record critical temperature (the phase transition temperature below which superconductivity occurs) is today 138 K (-135 °C). This new class of superconductors, which are easier and cheaper to use, has given fresh impetus to the race to find ever higher critical temperatures, with the ultimate goal of obtaining materials which are superconducting at room temperature. However, until now, researchers have been held back by some fundamental questions. What causes superconductivity at microscopic scales" How do electrons behave in such materials"
Researchers at the National Laboratory for Pulsed Magnetic Fields2, working together with researchers at Sherbrooke, have observed 'quantum oscillations', thanks to their experience in working with intense magnetic fields. They subjected their samples to a magnetic field of as much as 62 teslas (a million times stronger than the Earth's magnetic field), at very low temperatures (between 1.5 K and 4.2 K). The magnetic field destroys the superconducting state, and the sample, now in a normal state, shows an oscillation of its electrical resistance as a function of the magnetic field. Such an oscillation is characteristic of metals: it means that, in the samples that were studied, the electrons behaved in the same way as in ordinary metals.
The researchers will be able to use this discovery, which has been eagerly awaited for 20 years, to improve their understanding of critical high-temperature superconductivity, which until now had resisted all attempts at modeling it. The discovery has been effective in sorting out the many theories which had emerged to explain the phenomenon, and provides a firm foundation on which to build a new theory. It will make it possible to design more efficient materials, with critical temperatures closer to room temperature.
CNRS
Researchers at the National Laboratory for Pulsed Magnetic Fields2, working together with researchers at Sherbrooke, have observed 'quantum oscillations', thanks to their experience in working with intense magnetic fields. They subjected their samples to a magnetic field of as much as 62 teslas (a million times stronger than the Earth's magnetic field), at very low temperatures (between 1.5 K and 4.2 K). The magnetic field destroys the superconducting state, and the sample, now in a normal state, shows an oscillation of its electrical resistance as a function of the magnetic field. Such an oscillation is characteristic of metals: it means that, in the samples that were studied, the electrons behaved in the same way as in ordinary metals.
The researchers will be able to use this discovery, which has been eagerly awaited for 20 years, to improve their understanding of critical high-temperature superconductivity, which until now had resisted all attempts at modeling it. The discovery has been effective in sorting out the many theories which had emerged to explain the phenomenon, and provides a firm foundation on which to build a new theory. It will make it possible to design more efficient materials, with critical temperatures closer to room temperature.
CNRS
Superconductivity Current Events and Superconductivity News RSSNIST demonstrates 'universal' programmable quantum processor
Physicists at the National Institute of Standards and Technology (NIST) have demonstrated the first "universal" programmable quantum information processor able to run any program allowed by quantum mechanics-the rules governing the submicroscopic world-using two quantum bits (qubits) of information.
Quantum gas microscope offers glimpse of quirky ultracold atoms
Physicists at Harvard University have created a quantum gas microscope that can be used to observe single atoms at temperatures so low the particles follow the rules of quantum mechanics, behaving in bizarre ways.
Rutgers physicists discover novel electronic properties in two-dimensional carbon structure
Rutgers researchers have discovered novel electronic properties in two-dimensional sheets of carbon atoms called graphene that could one day be the heart of speedy and powerful electronic devices.
Putting a Strain on Nanowires Could Yield Colossal Results
In finally answering an elusive scientific question, researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have shown that the selective placement of strain can alter the electronic phase and its spatial arrangement in correlated electron materials.
Scientists detect 'fingerprint' of high-temp superconductivity above transition temperature
A team of U.S. and Japanese scientists has shown for the first time that the spectroscopic "fingerprint" of high-temperature superconductivity remains intact well above the super chilly temperatures at which these materials carry current with no resistance.
Superconductivity: Which one of these is not like the other?
Superconductivity appears to rely on very different mechanisms in two varieties of iron-based superconductors.
Argonne, UC scientists reach milestone in study of emergent magnetism
Scientists at the U.S. Department of Energy's Argonne National Laboratory and the University of Chicago have reached a milestone in the study of emergent magnetism.
Thinnest superconducting metal created
A superconducting sheet of lead only two atoms thick, the thinnest superconducting metal layer ever created, has been developed by physicists at The University of Texas at Austin.
Evidence of macroscopic quantum tunneling detected in nanowires
A team of researchers at the University of Illinois has demonstrated that, counter to classical Newtonian mechanics, an entire collection of superconducting electrons in an ultrathin superconducting wire is able to "tunnel" as a pack from a state with a higher electrical current to one with a notably lower current, providing more evidence of the phenomenon of macroscopic quantum tunneling.
Multiferroics -- making a switch the electric way
Multiferroics are materials in which unique combinations of electric and magnetic properties can simultaneously coexist.
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Introduction to Superconductivity: Second Edition (Dover Books on Physics) (Vol i) by Michael Tinkham (Author) Accessible to graduate students and experimental physicists, this volume emphasizes physical arguments and minimizes theoretical formalism. Topics include the Bardeen-Cooper-Schrieffer and Ginzburg-Landau theories, magnetic properties of classic type II superconductors, the Josephson effect, fluctuation effects in classic superconductors, high-temperature superconductors, and nonequilibrium superconductivity. 109 figures. 1996 edition. |
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Superconductivity: A Very Short Introduction (Very Short Introductions) by Stephen J. Blundell (Author) Superconductivity--the flow of electric current without resistance in certain materials as temperatures near absolute zero--is one of the greatest discoveries of 20th century physics, but it can seem impenetrable to those who lack a solid scientific background. Outlining the fascinating history of how superconductivity was discovered, and the race to understand its many mysterious and counter-intuitive phenomena, Stephen Blundell explains in accessible terms the theories that have been developed to explain it, and how they have influenced other areas of science, including the Higgs boson of particle physics and ideas about the early Universe. This Very Short Introduction examines the many strange phenomena observed in superconducting materials, the latest developments in high-temperature... |
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Superconductivity, Second Edition by Charles P. Poole Jr. (Author), Horacio A. Farach (Author), Richard J. Creswick (Author), Ruslan Prozorov (Author) Superconductivity, 2E is an encyclopedic treatment of all aspects of the subject, from classic materials to fullerenes. Emphasis is on balanced coverage, with a comprehensive reference list and significant graphicsfrom all areas of the published literature. Widely used theoretical approaches are explained in detail. Topics of special interest include high temperature superconductors, spectroscopy, critical states, transport properties, and tunneling. This book covers the whole field of superconductivity from both the theoretical and the experimental point of view. - Comprehensive coverage of the field of superconductivity - Very up-to date on magnetic properties, fluxons, anisotropies, etc. - Over 2500 references to the literature... |
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Superconductivity, Superfluids, and Condensates (Oxford Master Series in Condensed Matter Physics) by James F. Annett (Author) Superconductivity, provides a basic introduction to one of the most innovative areas in condensed matter physics today. This book includes ample tutorial material, including illustrations, chapter summaries, graded problem sets, and concise examples. This book is part of the Oxford Master Series in Condensed Matter Physics. |
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Theory Of Superconductivity (Advanced Book Classics) by J. Robert Schrieffer (Author) Theory of Superconductivity is considered one of the best treatments of the field. This monograph, by Nobel Prize-winning physicist J. Robert Schrieffer, has been reprinted because of its enduring value as an introduction to the theory of superconductivity. Based on a series of lectures presented by the author at the University of Pennsylvania, the fundamentals of the theory of superconductivity are stressed as a means of providing the reader with a framework for the literature in which detailed applications of the microscopic theory are made to specific problems. It also serves as a foundation for the more recent developments in this active field. |
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Superconductivity by J. B. Ketterson (Author), S. N. Song (Author) This is a text on superconductivity, an area of intense research activity worldwide. The book is in three parts. The first covers the London, Pippard and GinzburgSHLandau theories, which are used to discuss a wide range of phenomena involving surface energies, vorticity, the intermediate and mixed states, boundaries and boundary conditions, the upper critical field in bulk, thin film and anisotropic superconductors, and surface superconductivity. The second part discusses the microscopic theory of Bardeen, Cooper and Schrieffer. The theory is used to discuss quasi particle tunneling and the Josephson effects from a microscopic point of view. The final part of the book treats nonuniform superconductors using the BogoliubovSHde Gennes approach with which it is possible to extract many... |
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Superconductivity by V. L. Ginzburg (Author), E. A. Andryushin (Author) What is superconductivity? How was it discovered? What are the properties of superconductors, how are they applied now, and how are they likely to become widely used in the near future? These are just some of the questions which this important book sets out to answer. Starting with the discovery of superconductivity over ninety years ago, the book guides the readers through the many years of subsequent exploration, right up to the latest sensational findings. Written in a lively, nontechnical style, this book makes ideal background reading for any school or college level study of superconductivity. The authors, who are leading authorities in the field, paint detailed pictures of the phenomena involved without mathematical formalism, appealing instead to physical intuition. |
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The Theory of Superconductivity in the High-Tc Cuprate Superconductors by P. W. Anderson (Author) This book is P. W. Anderson's long-awaited full presentation of his theory of high-Tc superconductivity in the cuprates. He realized that this striking new phenomenon needed for its explanation not just a new mechanism or "gimmick" but a radical reworking of the electronic theory of metals, especially those of low dimension. The many fundamentally new ideas that are first fully presented here will require a rewriting of the textbooks of many-body theory, which may take decades. The book incorporates full discussions of the experimental situation in these complex materials, both the normal and the superconducting states. The latest advances are contained in a selection of re-and pre-prints of recent work by Anderson and collaborators. The fundamental insight contained in the book is... |
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Superconductivity Of Metals And Alloys (Advanced Book Classics) by P. G. De Gennes (Author) Drawn from the author's introductory course at the University of Orsay, Superconductivity of Metals and Alloys is intended to explain the basic knowledge of superconductivity for both experimentalists and theoreticians. These notes begin with an elementary discussion of magnetic properties of Type I and Type II superconductors. The microscopic theory is then built up in the Bogolubov language of self-consistent fields. This text provides the classic, fundamental basis for any work in the field of superconductivity. |
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Superfluidity and Superconductivity (Graduate Student Series in Physics) by D.R. Tilley (Author), J Tilley (Author) Superfluidity and Superconductivity, Third Edition introduces the low-temperature phenomena of superfluidity and superconductivity from a unified viewpoint. The book stresses the existence of a macroscopic wave function as a central principle, presents an extensive discussion of macroscopic theories, and includes full descriptions of relevant experimental results throughout. This edition also features an additional chapter on high-temperature superconductors. With problems at the end of most chapters as well as the careful elaboration of basic principles, this comprehensive survey of experiment and theory provides an accessible and invaluable foundation for graduate students studying low-temperature physics as well as senior undergraduates taking specialized courses. |
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