Etch-a-sketch with superconductors

August 23, 2011

Reporting in Nature Materials this week, researchers from the London Centre for Nanotechnology and the Physics Department of Sapienza University of Rome have discovered a technique to 'draw' superconducting shapes using an X-ray beam. This ability to create and control tiny superconducting structures has implications for a completely new generation of electronic devices.

Superconductivity is a special state where a material conducts electricity with no resistance, meaning absolutely zero energy is wasted.

The research group has shown that they can manipulate regions of high temperature superconductivity, in a particular material which combines oxygen, copper and a heavier, 'rare earth' element called lanthanum. Illuminating with X-rays causes a small scale re-arrangement of the oxygen atoms in the material, resulting in high temperature superconductivity, of the type originally discovered for such materials 25 years ago by IBM scientists. The X-ray beam is then used like a pen to draw shapes in two dimensions.

A well as being able to write superconductors with dimensions much smaller than the width of a human hair, the group is able to erase those structures by applying heat treatments. They now have the tools to write and erase with high precision, using just a few simple steps and without the chemicals ordinarily used in device fabrication. This ability to re-arrange the underlying structure of a material has wider applications to similar compounds containing metal atoms and oxygen, ranging from fuel cells to catalysts.

Prof. Aeppli, Director of the London Centre for Nanotechnology and the UCL investigator on the project, said: "Our validation of a one-step, chemical-free technique to generate superconductors opens up exciting new possibilities for electronic devices, particularly in re-writing superconducting logic circuits. Of profound importance is the key to solving the notorious 'travelling salesman problem', which underlies many of the world's great computational challenges. We want to create computers on demand to solve this problem, with applications from genetics to logistics. A discovery like this means a paradigm shift in computing technology is one step closer."

Prof Bianconi, the leader of the team from Sapienza, added: "It is amazing that in a few simple steps, we can now add superconducting 'intelligence' directly to a material consisting mainly of the common elements copper and oxygen."

The X-ray experiments were performed at the Elettra (Trieste) synchrotron radiation facility. The work is published in Nature Materials , 21 August 2011 (doi:1038/nmat3088) and follows on from previous discovery of fractal-like structures in superconductors (doi:10.1038/nature09260).

University College London

---

---

	Superconductivity: A Very Short Introduction 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...
	Introduction to Superconductivity: Second Edition (Dover Books on Physics) (Vol i) by Michael Tinkham (Author), Physics (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.
	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 that...
	The Breakthrough: The Race for the Superconductor by Robert M. Hazen (Author)
	Theory of Fluctuations in Superconductors (International Series of Monographs on Physics) by Anatoly Larkin (Author), Andrei Varlamov (Author) This book presents a complete encyclopaedia of superconducting fluctuations, summarising the last thirty-five years of work in the field. The first part of the book is devoted to an extended discussion of the Ginzburg-Landau phenomenology of fluctuations in its thermodynamical and time-dependent versions and its various applications. The second part deals with microscopic justification of the Ginzburg-Landau approach and presents the diagrammatic theory of fluctuations. The third part is devoted to a less-detailed review of the manifestation of fluctuations in observables: diamagnetism, magnetoconductivity, various tunneling characteristics, thermoelectricity, and NMR relaxation. The final chapters turn to the manifestation of fluctuations in unconventional superconducting systems:...
	Nanostructured Superconductors by Victor V. Moshchalkov (Author), Joachim Fritzsche (Author) The main focus of the book is to present the effects of nanostructuring on superconducting critical parameters. Optimizing systematically flux and condensate confinement in various nanostructured superconductors, ranging from single nano-cells to their huge arrays, critical fields and currents can be increased up to their theoretical limits, thus drastically improving the potential for practical applications of nanostructured superconductors.
	Applications of High Temperature Superconductors to Electric Power Equipment by Swarn S. Kalsi (Author) The only one-stop reference to design, analysis, and manufacturing concepts for power devices utilizing HTS.High temperature superconductors (HTS) have been used for building many devices for electric grids worldwide and for large ship propulsion motors for the U.S. Navy. And yet, there has been no single source discussing theory and design issues relating to power applications of HTS—until now. This book provides design and analysis for various devices and includes examples of devices built over the last decade.Starting with a complete overview of HTS, the subsequent chapters are dedicated to specific devices: cooling and thermal insulation systems; rotating AC and DC machines; transformers; fault current limiters; power cables; and Maglev transport. As applicable, each chapter...
	Superconductor/Semiconductor Junctions (Springer Tracts in Modern Physics) by Thomas Schäpers (Author) This book, featuring the most comprehensive treatment of Josephson junctions ever published, describes superconductor/two-dimensional-electron-gas (2DEG) structures, providing a better understanding of their transport properties. It also discusses the control of junctions using gate electrodes or injection currents, and the physical effects observed in these junctions.
	High-Temperature Cuprate Superconductors: Experiment, Theory, and Applications (Springer Series in Solid-State Sciences) by Nikolay Plakida (Author) High-Temperature Cuprate Superconductors provides an up-to-date and comprehensive review of the properties of these fascinating materials. The essential properties of high-temperature cuprate superconductors are reviewed on the background of their theoretical interpretation. The experimental results for structural, magnetic, thermal, electric, optical and lattice properties of various cuprate superconductors are presented with respect to relevant theoretical models. A critical comparison of various theoretical models involving strong electron correlations, antiferromagnetic spin fluctuations, phonons and excitons provides a background for understanding of the mechanism of high-temperature superconductivity. Recent achievements in their applications are also reviewed. A large number of...
	Neutron Scattering in Layered Copper-Oxide Superconductors (Physics and Chemistry of Materials with Low-Dimensional Structures) by Albert Furrer (Editor) This is the first book which reviews the most important results obtained in the past decade for layered copper-oxide high-temperature superconductors by neutron scattering techniques. The following topics are thoroughly introduced, methodically discussed and highlighted with the most important results by acknowledged experts in their respective fields: static and dynamical properties of the crystal lattice (oxygen site occupation, charge transfer, charge-stripe order, phonon dispersions and density-of-states), static and dynamical magnetic correlations (phase diagrams, 2D and 3D magnetic ordering, spin waves and spin fluctuations, crystal-field excitations) and the structure of the flux-line lattice (field and temperature dependence). The 2D features of the copper-oxide...