Guy Deutscher, a deep and valuable scientist and a very pleasant person, dies at 88

Guy Deutscher was born in Berlin in 1936. The Jewish family decided to leave Germany in 1939, just before World War II, travelling to Paris where the family was arrested during the Vélodrome d'Hiver (Vél d'Hiv) Roundup (1942) but finally Guy and his mother escaped from being deported to Auschwitz and reunited with his father at the end of the war. After the war he remained in Paris where he completed High School in 1953 and in 1959 he obtained the Engineering Degree of Mines, with Metallurgy specialization. After three years of military service he was accepted in the research group of Prof. Pierre Gilles de Gennes who would become Physics Nobel Prize in 1991 at the Paris-Sud University. The group was known as the “Superconductivity group of Orsay”. Guy obtained his PhD (1966) investigating the proximity effects in superconductors. He moved for a year to complete his post-doc with the group led by Bernie Serin (co-discoverer of the isotope effect in superconductors), with Peter Lindenfeld and Bill McLean at Rutgers University (USA) and then he was back to France where he was Associated Professor at Paris-Orsay. Finally, in 1971 he decided to move to Israel at the Tel Aviv University where he was nominated Professor and where he stayed during 54 years for all his scientific career. He kept both French and Israeli nationalities.

His scientific interests were very broad. During his career Guy developed a special interest for the topic of disordered materials where he made many well-known contributions to the physics of granular superconductors, a topic which allowed him to write his first book “Percolation, structures and processes” in 1983.

After the discovery of High Temperature Superconductors (HTS) in 1986 he was the first, in an article published together with the Nobel Prize K.A. Muller in 1987, to stress how relevant was the short coherence length in HTS to generate a granular behavior. This publication has been the most cited one in his scientific career.

During his long scientific career investigating the HTS materials. Guy made many more relevant scientific contributions. For instance, his views about the normal metal – superconductor contacts (Andreev reflections), tunnel junctions, as well as his analysis of pair coherence in the pseudogap and in the overdoped states of HTS, were very insightful to understand the energy scales involved in the electronic excitations of HTS. Certainly, his theoretical insights were always comprehensive but keeping a strong proximity to the experimental works, as it was in his early times at Orsay. Several of his articles in these fields are among those having received more citations in his scientific life. Guy was actively publishing very appealing articles about these topics until his last days.

But Guy was not only interested in fundamental aspects of superconductivity, he was also strongly motivated to analyze how to enhance the performance of HTS materials to achieve a strong impact in electronics and energy applications. For that reason, he was following in detail the developments of vortex pinning issues in HTS, including understanding the origin of the Irreversibility Line and proposing new ideas about how to achieve enhanced critical currents in coated conductors and also in the control of tunnel junctions for electronics. This is clearly ascertained with the in-depth presentation of the topics dealt in his second book: “New superconductors: from granular to high Tc” (World Scientific, 2006), where many aspects of the different challenges of these complex materials are very clearly discussed. Guy was a scientist with strong links to several of the best scientists of his time, with contact and friendship with other colleagues who have strongly influenced the field of superconductivity, such as P.G. de Gennes, V. Ginzburg, K.A. Muller and J. Friedel.

I’m personally deeply indebted to Guy Deutscher for how much I learned from him about superconductivity. I never had the opportunity to chat with another scientist with such a broad culture and a deep understanding of the phenomena as well as such an open vision about how relevant were the experiments. I still remember performing nice walks around the beautiful Lake Orta, in the north of Italy, where Massimo Marezio, another visionary of HTS materials, organized very pleasant meetings of the European Network SCENET. These discussions and pleasant walks were the origin of a long term friendship and many collaborations, common visits and exchanges between the groups of ICMAB in Barcelona and that of Tel Aviv. We published half a dozen of collaborating articles in common where the deep insights of Guy were always key to reach a high impact, achieving more than 400 citations. I’m certainly very grateful for his extraordinary vision which deepened the impact of our work.

More recently, we had the opportunity to become collaborating partners in the scope of the European project FASTGRID, coordinated by Prof. Pascal Tixador from CNRS Grenoble, intending to develop a dc superconducting fault current limiter with HTS. From the Tel Aviv – ICMAB – CNRS collaboration we reached very promising new current limiting elements based on saphire substrates. The innovative work at Tel Aviv demonstrated how sensitive was Guy to promote the use of HTS materials to push clean energy applications.

Guy Deutscher has not only been a very fruitful and active scientist, he was also very active in mentoring young scientists, promoting research around him, undertaking activities to outreach the physics discoveries, and discussing the huge environmental and economic impact of the modern use of non-renewable energy. He wrote very insightful books about these topics, for instance “The Climate Debt: Combining the Science, Politics and Economics of Climate Change” (World Scientific, 2023). He was also the Editor-in-Chief of a series of books in “Applications of Superconductivity and Related Phenomena” and he was an active member of the Commission of the International Agency of Energy involved in analyzing the paths to accelerate the international implementation of HTS power systems in the electrical grid. He was very happy to see in his last days the birth of the “compact fusion revolution” based on powerful HTS magnets, because he was convinced that it is one of the best technological opportunities that human kind has to reverse the entropic evolution of the planet, and so paying in part the climate debt that we leave to our descendants.

Because of his scientific leadership and his merits in creating a superconductivity community (Gordon Center of Energy Studies, Heinrich Hertz-Minerva Center for High-Temperature Superconductivity) he received many awards and honors, for instance, the Incumbent Oren Family Chair of Experimental Solid State Physics at Tel Aviv University (1981), honors from the Israel Physical Society and the French Government (Palmes Academiques - 1986); Chévalier de la Légion d’Honneur - 1999), and The Israel Vacuum Society (IVS) Excellency Award for Research (2012).
Guy leaves an outstanding academic legacy with a strong impact in the field of superconductivity. We certainly leave a very good friend and a highly appreciated colleague. He is followed by his dear wife Aline with whom he shared a long and fruitful life and by his daughter Nathalie and his son Daniel and their families.

Xavier Obradors, Institut de Ciència de Materials de Barcelona (CSIC), Catalonia, Spain

Image courtsey of Roybeckbarkai, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0&gt;, via Wikimedia Commons