Prof. Dr. Thorsten Jungmann (last updated 2026-10-03)
Eugène Bloch (1878–1944) was a French physicist and professor at the École normale supérieure and at the Faculty of Science of the University of Paris. He was born on 10 June 1878 in Soultz-Haut-Rhin, Alsace-Lorraine, then part of the German Empire. His father, an industrialist in the textile industry, settled in Paris to give his two sons a French education. Bloch studied at the École normale supérieure from 1897 to 1900 and defended his doctoral thesis on the electrical conductivity of air produced by phosphorus at the University of Paris in 1904. From 1906 he taught as professor of physics at the Saint-Louis secondary school in Paris and carried out research on the photoelectric effect and on spectroscopy in the physics laboratory of the École normale supérieure. His experiments on the photoelectric effect helped to support the interpretation given by Albert Einstein in 1905.
Bloch is known for designing the first multivibrator (German: Kippstufe) together with Abraham during the First World War. This Abraham–Bloch multivibrator is an astable multivibrator: it consisted of two vacuum tube amplifiers cross-coupled by a resistor–capacitor network, is not stable in either state and continually switches from one state to the other. It thus functions as a relaxation oscillator. Abraham and Bloch called it a multivibrateur because its output waveform was rich in harmonics.
In 1940 Bloch was dismissed from his professorship under the anti-Jewish laws of the Vichy government. He worked in a laboratory of the University of Lyon and then took refuge under a false identity in Savoy and the Dauphiné; after a failed attempt to cross into Switzerland he hid in the mountains. The Gestapo arrested him at Allevard (Isère) on 24 January 1944. He was deported to the Auschwitz concentration camp, where he was murdered. The Three Physicists Prize is named after Abraham, Bloch and Georges Bruhat, who all died in deportation in Nazi camps.
Reference and further reading:
https://en.wikipedia.org/wiki/Eugene_Bloch
https://en.wikipedia.org/wiki/Multivibrator