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discovered 02_2012

FOCUS// The HZDR Research Magazine WWW.Hzdr.DE 10 11 This situation changes as soon as a magnetic field affects the superconductor. “The electrons then attempt to realign themselves with the magnetic field and thus the Cooper pairs try to split“, Joachim Wosnitza explains. Since individual pairs cannot dance out of sync however, the magnetic field has to be relatively strong and has to invest a great deal of energy to make the dancers lose their rhythm and interrupt the superconductivity. This minimum amount of energy that is required is known to materials researchers as the “critical Zeeman energy“. Nano spots are still a mystery Together with Richard Ferrell, Peter Fulde already demonstrated back in 1964 (at least theoretically) that superconductivity should still be possible beyond this Zeeman energy, representing some kind of hybrid state: tiny, normally-conducting areas alternate with “superconducting nano spots“. “To be precise these are not really spots but rather a wave of superconductivity and normal conductivity that evolves in the material“, describes HZDR researcher Joachim Wosnitza. Because around the same time two other physicists also predicted this superconductivity state beyond the Zeeman energy, it is now called the “Fulde-Ferrell-Larkin- Ovchinnikov superconducting state“. To non-physicists however this effect abbreviated as “FFLO“ still remains a mystery. In order to explain these processes to laymen, Peter Fulde uses a very vivid analogy, even if it tends to oversimplify the process. If we imagine that the electrons with a downward spin represent the men, then the electrons with an upward spin would represent the women. In human societies women and men unite in a similar way as the electrons that form Cooper pairs, which are important for superconductivity. When there are too many males If for some reason there are more males than females in society, this soon leads to unrest: “the surplus males also Professor Peter Fulde The founding director of the Max Planck Institute for the Physics of Complex Systems (MPIPKS) likes to spend a lot of his time these days in South Korea, where he is very much in demand as a consultant – and as an emeritus director he also has sufficient time for it. As of this year he has had a seat on the Scientific Board of Directors at the Korea Basic Science Institute while also being president of the Institute’s Central Election and Evaluation Committee. Since 2007 he has also been a professor at the Pohang University for Science and Technology (POSTECH) and president of the Asia Pacific Center for Theoretical Physics that is also located in Pohang, South Korea. Saxony also has a lot to thank Peter Fulde for. Not only for the fact that, after his time spent as director at the Max Planck Institute for Solid State Research in Stuttgart, in 1993 he founded the Max Planck Institute for the Physics of Complex Systems in Dresden, whose director he was until 2007. He was an active consultant here (as well as in many other places) for many years in various institutes and boards, and has a very high reputation. In this way Peter Fulde was able to considerably influence the development of the Helmholtz-Zentrum Dresden-Rossendorf, for which he was awarded the status of honorary member in 2009. During his time as a member on the supervisory board of the center from 2000 to 2008 he had other roles in an honorary capacity such as being on the supervisory board of the PTB (Germany’s national metrology institute) and on the supervisory board of the Frankfurt Institute for Advanced Studies (FIAS) or as chair of the Material and Technology Section of the Max Planck Society. To name only a few national as well as international offices and stations: member of Saxony’s Research Council as well as the Scientific Council of the Federal Republic of Germany, trustee of the German-Israeli Foundation, founding member of the Berlin-Brandenburg Academy of Sciences, member of the Leopoldina in Halle as well as the German National Academy of Science and Engineering (acatech). The list seems endless for the exceptional physicist born in Breslau in 1936. Admittedly, Peter Fulde has already received numerous awards and honorary titles, but this magazine’s editors are convinced that the discovery of the “Fulde effect“ named after him certainly merits yet another scientific award. WWW.Hzdr.DE 10 11