科学者が語る科学の楽しみ

J. Georg Bednorz
1987年 ノーベル物理学賞受賞

【研究実績】

1. 1982年1月

   IBM入社、スイス、チューリヒ、Ruschklikon, IBM Zurich Research Lab.

2. 1987年夏

   チューリヒ、スイス・フェデラル・インスティテュート・オブ・テクノロジー 講師

【カール・アレックスミューラー博士と共に以下の賞を受賞しました】

1. 1987年

   The Thirteenth Fritz London Memorial ]award (presented by the Fritz LondonMemorial award Committee, University of California, Los Angeles)

2. 1987年

   The Dannie Heineman Prize (awarded by the Minna James Heineman Stiftung, Academy of sciences Gottingen, West Germany)

3. 1987年

   The Robert Wichard Pohl Prize (conferred by the Prize Committee and The Steering Committee of the German Physical Society)

4. 1988年

   The 1988 Hewlett-Packard Europhysics Prize

5. 1986年

   The Marcel-Benoist Prize Conferred by the Marcel-Benoist Foundation, chaired by Flavio cotti, member of the Federal Council

6. 1987年

   The Novel Prize in Physics

7. 1988年

   The 1988 APS International Prize for New Materials Research and the Minnie Rosen Award,conferred by the Ross University, New York

8. 1987年

   Viktor Moritz Goldschmidt Prize awarded by the German Mineralogical Society

9. 1987年

   The Otto-Klung Prize awarded by the Otto-Klung Foundation, Free University of Berlin, West Germany

Ten Years of High-Temperature Superconductivity - Years of Challenges and Surprises for Science and Technology

While writing this address to young Japanese scientists, I recall that exactly 10 years ago my colleague K. Alex Mueller and I were making the final revisions on our manuscript about "Possible High-Temperature Superconductivity in the Ba-La-Cu-O System", which marked the beginning of a new and fascinating epoch in superconductivity research.
When continuing our research on the magnetic properties of the cuprate superconductor, we were almost certain that our results would meet substantial skepticism in the scientific community; the greater was our surprise when by the end of 1986 we learned that numerous groups throughout the world had started to follow our approach in the search for high-temperature superconductors.
　
Chemical modification of the original compound led to the discovery of new cuprate phases with the record transition temperatures rising at a rapid pace. This, however, also increased the level of expectation concerning the time scale for the realization of practical applications. As scientists and engineers were facing numerous technical problems arising from the specific properties of the cuprates, applications could not keep up with the speed at which new compounds were discovered. The list of achievements made in the past decade is impressive, and the continuous progress reflects a concentrated effort worldwide.
　
We recall obstacles caused by the specific material properties, which initially seemed to rule out any meaningful application of the ceramic layered cuprates. With the fabrication of epitaxial films, however, it was possible to demonstrate critical current densities of several million Amperes per cubic centimeter as compared to a few hundred in bulk ceramics. Subsequently, thin films became increasingly important as model systems to study various effects due to the material properties.
　
experiments had significant impact on the methods of processing bulk superconductors, in which customization on the atomic level could enhance the critical current densities up to a few thousand Amperes per cubic centimeter. Today, bulk high-temperature superconductors in the form of massive components are used for a host of prototypes ranging from current leads, current limiters, magnetic bearings and - in form of tapes and wires - to magnets, motors, generators, transformers and flexible cables for power transmission.
　
Much closer to the market are applications based on thin epitaxial films. So-called SQUIDs (Superconducting Quantum Interference Devices) for the detection of very weak magnetic fields, for example, turned out to be superior to low-temperature superconductor versions. The highest market share, however, could have high-temperature superconductor microwave components, such as high-quality resonators, stable oscillators, antennas, filters and delay lines.
　
With all these achievements, the role of high-temperature superconductors in future technology seems evident. But beyond this, customized cuprates and their specific properties may play a significant role in impacting new technologies, probably with applications that at present lie beyond our imagination.
　
Why should we be prepared for new surprises? Well, because the subject of high-temperature superconductivity has changed our scientific and technical environment. On the one hand, with the cuprates as a vehicle, we are improving our skills in creating materials by "engineering" on the atomic scale and in performing ultrasensitive analysis. The methods we employ to grow thin films of artificial superlattices can easily be applied to a larger class of oxides as can the experiments originally designed for the superconductors.
　
On the other hand, and possibly even more important, we have changed our way of collaboration. With the high-temperature superconductors as a stimulus and a point of common interest, collaborative efforts were established across all disciplines in solid-state sciences, and - despite a strong competitive element in the field - with so far unprecedented intensity on an international level. The example of high-temperature superconductivity shows the vast potential that can be activated when multidisciplinary and multicultural thinking is involved. The success should create the desire not only to preserve the current status of collaborative efforts but to extend these to further scientific and technological topics.

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