沃尔特·海特勒1904—1981

Walter Heinrich Heitler (German: [ˈvaltɐ ˈhaɪnʁɪç ˈhaɪtlɐ]; 2 January 1904 – 15 November 1981) was a German theoretical physicist who made contributions to quantum electrodynamics and quantum field theory. He brought chemistry under quantum mechanics through his theory of valence bonding.

Education

Walter Heinrich Heitler was born on 2 January 1904 in Karlsruhe, Grand Duchy of Baden, German Empire, the son of Ottilie (née Rudolf) and Adolf Heitler, a Jewish engineering professor.

Heitler studied physical chemistry at LMU Munich, where he received a Doctor of Philosophy in 1926 under the supervision of Karl Herzfeld. He was a Rockefeller Foundation Fellow for postgraduate research with Niels Bohr at the University of Copenhagen in 1926 and with Erwin Schrödinger at the University of Zurich the following year. He then became an assistant to Max Born at the University of Göttingen, where he completed his habilitation in 1929. Heitler remained at Göttingen as a Privatdozent until 1933, when he was dismissed by the university on the grounds of his Jewish ancestry.

Career and research

At the time Heitler obtained his doctorate, three Institutes for Theoretical Physics formed a consortium which worked on the key problems of the day, such as atomic and molecular structure, and exchanged both scientific information and personnel in their scientific quests. These institutes were located at the Ludwig-Maximilians-Universität München, under Arnold Sommerfeld; the University of Göttingen, under Max Born; and the University of Copenhagen, under Niels Bohr. Furthermore, Werner Heisenberg and Born had just recently published their trilogy of papers which launched the matrix mechanics formulation of quantum mechanics. Also, in early 1926, Erwin Schrödinger, at the University of Zurich, began to publish his quintet of papers which launched the wave mechanics formulation of quantum mechanics and showed that the wave mechanics and matrix mechanics formulations were equivalent. These papers immediately put the personnel at the leading theoretical physics institutes onto applying these new tools to understanding atomic and molecular structure. It was in this environment that Heitler used his Rockefeller Foundation Fellowship, leaving the Ludwig-Maximilians-Universität München and within a period of two years going to do research and study with the leading figures of the day in theoretical physics—Bohr at the University of Copenhagen, Schrödinger at the University of Zurich, and Born at the University of Göttingen.

At the University of Zurich, with Fritz London, Heitler applied the new quantum mechanics to deal with the saturable, non-dynamic forces of attraction and repulsion, i.e., exchange forces, of the hydrogen molecule. Their valence bond treatment of this problem, was a landmark in that it brought chemistry under quantum mechanics. Furthermore, their work greatly influenced chemistry through Linus Pauling, who had just received his doctorate and on a Guggenheim Fellowship visited Heitler and London in Zurich. Pauling spent much of his career studying the nature of the chemical bond. The application of quantum mechanics to chemistry would be a prominent theme in Heitler's career.

Bristol

While Heitler was at Göttingen, Adolf Hitler came to power in 1933. With the rising prominence of anti-Semitism under Hitler, Born took it upon himself to take the younger Jewish generation under his wing. In doing so, Born arranged for Heitler to get a position that year as a research fellow at the University of Bristol, with Nevill Francis Mott.

Heitler was a research fellow of the Academic Assistance Council in the H. H. Wills Physics Laboratory. Among other things, he worked on quantum field theory and quantum electrodynamics on his own, as well as in collaboration with other scientific refugees from Hitler, such as Hans Bethe and Herbert Fröhlich, who also left Germany in 1933.

With Bethe, he published a paper on pair production of gamma rays in the Coulomb field of an atomic nucleus, in which they developed the Bethe–Heitler formula for Bremsstrahlung (braking radiation).

In 1936, Heitler published his major work on quantum electrodynamics, The Quantum Theory of Radiation, which marked the direction for future developments in quantum theory. The book appeared in many editions and printings and has been translated into Russian.

Heitler also contributed to the understanding of cosmic rays,

as well as predicting the existence of the electrically neutral pi meson.