September 9, 1922, Görlitz (Germany) – March 7, 2017, Seattle (United States)
At the age of 10, he began his studies at a Latin school, the Gymnasium in Grauen Kloster, in Berlin (Germany). In 1940 he graduated and voluntarily enlisted in the German Army.
In 1943, the army detects his potential as a scientist and orders him to enter the University of Breslau (the current Polish city of Wroclaw) to study Physics. However, during the Battle of the Bulge he was taken prisoner.
Three years later he was released from an American prison camp and returned to study at the University of Göttingen (Germany), one of the most advanced scientific centers of its time. There he obtained a doctor's degree in 1950 and, in 1952, he was invited to do a postdoctoral stay at Duke University (United States) for which he emigrated.
His outstanding career led him to be a professor at the University of Washington in Seattle (United States), first as assistant (1955-1958), associate (1958-1961) and, finally, full professor of Theoretical Physics (1961-2002). The year after obtaining this position that guaranteed his employment status, Dehmelt applied for and obtained US citizenship.
His investigations focused mainly on the study of the primary components of matter and the methods of their isolation, allowing the advancement of microphysics, such as, for example, the increase in precision of the measurements of atomic frequencies and of the transactions between atomic energy levels.
In the 1950s, Wolfgang Pauli devised the so-called "Penning trap", an experimental method that allows a small number of electrons and other charged particles to be trapped for long periods using two fields (a static, magnetic, and strong one). , and another electric and weak).
Dehmelt perfected this trap until, for the first time in 1973, he was able to retain an isolated electron for many hours, which in turn allowed him to study it in depth and make highly precise measurements of its properties. The great advance was that, until then, all classical measurements came from data obtained on millions of electrons at the same time, so one could only speak of estimates obtained by averaging.
Advancing his research, in 1975, Dehmelt managed to cool the particles by reducing their energy to measure them more precisely. These measurements refer to frequencies (quantum jumps), and to the magnetic moment of the electron, a measure of transcendental precision to test certain theories on quantum electronics. In this way, in 1986 he was able to detect a single quantum jump (ie, an excitation level transition) in an isolated barium ion in an electromagnetic trap.
Three years later, Dehmelt concluded that the electron and the positron have the same magnetic moment (with a possible error of one part in a trillion). Furthermore, as a result of his measuring work, he established a more precise value for the radius of the electron at 10-22 meters, that is, 1,000 times less than the upper limit previously calculated utilizing particle accelerators.
In 1989, he received the Nobel Prize in Physics, which he shared with the Americans Norman Foster Ramsey and Wolfgang Pauli for their contributions to modern microphysics.
