Ernst Ising

Ernst Ising ( born May 10, 1900 in Cologne, † 11 May 1998 in Peoria / Illinois, USA ) was a German mathematician and physicist.

Life

Ernst Ising's parents were of businessman Gustav Ising and his wife Thekla, born lion. After graduating from the Humanistic Gymnasium Bochum and a short military service Ernst Ising studied mathematics, physics and astronomy in Göttingen, Bonn and Hamburg. In his Wilhelm Lenz in Hamburg in 1922 commenced and completed in 1924 doctoral thesis, he analyzed a proposed by his doctor father model, which should contribute to the understanding of ferromagnetism, which was later named after him Ising model. The dissertation was published in 1925 in part, in Journal of physics. Because the consideration of Ernst Ising one-dimensional version of a spin chain, no parent ferromagnetism described, the resignation, but fortunately erroneous conclusion was in the thesis that the model probably unfortunately did not make any further particular interest because of its short-range interactions ("... so we arrive at our assumptions are not a statement of ferromagnetism ... It seems, therefore the conclusion justified that one of our assumptions is not true ").

After receiving his doctorate was Ernst Ising two years in the industry working ( patent department of AEG), before turning to the teaching profession. He studied pedagogy and philosophy in Berlin with the Magisterium exams for secondary schools 1930. Starting from 1927 he was at boarding school working in Salem. After that he was Studienassessor in Strausberg and Crossen. 1933 Ernst Ising was dismissed from government service because of his Jewish roots of the new regime in Germany. He found a job at the Jewish Children's and school camp in Caputh near Potsdam, where he replaced in 1937 Fridolin Friedmann as headmaster; Ernst and his wife Johanna "Jane" Ising, née Ehmer lived there in Caputh next to the now already former summer home of Albert Einstein family. In 1938 the school was devastated by Nazis in Caputh, 1939 emigrated to Ising to Luxembourg. After the occupation of Luxembourg (1940 ) by the German Wehrmacht Ernst Ising was committed over a year to forced labor during the dismantling of railroad tracks on the Maginot Line. 1947 emigrated Ising family to the United States.

Only then learned Ising that "his " model had become the subject of intense research. In particular, the exact solution of the model for a square lattice in two dimensions by Lars Onsager in 1944 attended by experts for a lot of attention: The model is, in the multi-dimensional version, but capable of converting a at higher temperatures magnetically disordered material into a ferromagnet to describe how in 1936 predicted qualitatively by Rudolf Peierls.

Ising was first a teacher at a college in Minot ( North Dakota). In 1948 he became a professor at Bradley University in Peoria (Illinois ). He worked there for several decades until his retirement in 1976 as a university teacher, without, except for a shorter letter to the editor of ' Goethe as a physicist ', to be published in professional journals. In 1953 he became U.S. citizens. In 1971 he received an award as "Outstanding Teacher of America".

In an obituary of Bradley University is: Ernst was a sensitive, artistic interested man of travel and loved the arts. He had a penetrating mind and a keen sense of humor, however, was of a gentle, quiet character, who was always a little embarrassed when he was asked about his famous model

In 1974 he was honored by the University of Hamburg on the occasion of his Golden Jubilee PhD.

Effect

With its numerous variants of the Ising model has become one of the most studied models in statistical physics ( and beyond). In particular, it is the starting point of basic descriptions of phase transitions in a range of materials with and without (eg, " random- bond Ising model " ) impurities of glassy (eg / -J model or Sherrington - Kirkpatrick model) and spatially modulated ( annni model) as well as structures of neural networks and learning processes ( Hopfield model). It is used to test numerical algorithms, such as Monte- Carlo simulations and transfer matrix calculations. "Simple Ising models quietly thrive " (Michael E. Fisher) seems to be an evergreen not only in statistical physics. Many experiments can be reproduced very well by the Ising model.

After the death of Ernst Ising, the University of Hamburg has launched an " Ernst Ising price", which was first awarded in 2002. In addition, the University of Hamburg named a junior professorship by Ernst Ising.