Prof. Hisao Hayakawa passed away on July 12, 2020.

A European Perspective of Prof. Hayakawa’s Scientific Life

After some informal contacts with Prof. Hayakawa in the early 1990s, a more frequent exchange of opinions about the future of Superconducting Electronics, especially digital electronics, started after the European Network of Excellence in Superconductivity (SCENET) of the European Community was founded in 1996. I headed the Superconducting Electronics activities and advised the European Community about projects and new developments in the field. Starting from that point in time, the communication with Prof. Hayakawa intensified and his advice was essential for a creating a number of European research projects for Superconducting Electronics. On the other hand, the European effort also stimulated projects in Japan, at that time primarily in High-Tc Electronics. Laboratory visits and project quality assessments were done mutually in the following years. Eventually, we tried to come to a longer-standing formal cooperation between Japanese Superconductivity Research programs and European ones, but due to the lack of industry interest in Digital Superconducting Electronics, only the materials-related part was granted by the European community. This about started the downhill trend of HTS-electronics research in Europe and Japan.

Apart from his activity in research management in the cooperation between Europe and Japan, Prof. Hayakawa was also a gifted speaker and pleasant colleague, open for serious discussions and fun – with colleagues and students equally. He presented the Japanese activities in digital superconducting electronics on various occasions in Europe. One meeting was especially memorable, the SCENET Superconducting Electronics Workshop which took place from 20 - 22 March 2003 in Tenerife, Spain. I cite from my report to the European Community:

“The opening talk by Prof. Hayakawa was an excellent overview over the current METI-financed activities in digital superconducting electronics in Japan. It became clear that we arrived at a very important decision point in digital superconducting electronics in Europe. We are still able to compete with Japanese activities, but we will for sure fall behind if no major funding will become available soon to intensify this type of research and technology development in Europe. Especially activities like the SCENET-initiated FLUXONICS initiative for a European foundry for superconducting electronics are essential for the technological future of Europe in superconducting electronics. As one of the results following the discussions after the talk, we agreed to investigate the possibility to cooperate with Japan in a number of areas, such as materials technology for superconducting electronics and the design of digital circuits for fast data processing. We intend to realize such a co-operation in first instance via Japanese/European workshops.”

The combination of his excellence, openness, and friendly and relaxed contact with everyone made him a giant in the international superconducting electronics field. After his retirement, he fully stopped working in superconducting electronics. In the following years, I had contact with him from time to time, but then on a strictly personal basis. We will miss him badly.

Horst Rogalla