Rudolf Peierls
Sir Rudolf Ernst Peierls, was a German-born British physicist who played a major role in Tube Alloys, Britain's nuclear weapon programme, as well as the subsequent Manhattan Project, the combined Allied nuclear bomb programme. His 1996 obituary in Physics Today described him as "a major player in the drama of the eruption of nuclear physics into world affairs".
Peierls studied physics at the University of Berlin, at the University of Munich under Arnold Sommerfeld, the University of Leipzig under Werner Heisenberg, and ETH Zurich under Wolfgang Pauli. After receiving his DPhil from Leipzig in 1929, he became an assistant to Pauli in Zurich. In 1932, he was awarded a Rockefeller Fellowship, which he used to study in Rome under Enrico Fermi, and then at the Cavendish Laboratory at the University of Cambridge under Ralph H. Fowler. Because of his Jewish background, he elected to not return home after Adolf Hitler's rise to power in 1933, but to remain in Britain, where he worked with Hans Bethe at the Victoria University of Manchester, then at the Mond Laboratory at Cambridge. In 1937, Mark Oliphant, the newly appointed Australian professor of physics at the University of Birmingham recruited him for a new chair there in applied mathematics.
In March 1940, Peierls co-authored the Frisch–Peierls memorandum with Otto Robert Frisch. This short paper was the first to set out that one could construct an atomic bomb from a small amount of fissile uranium-235. Until then it had been assumed that such a bomb would require many tons of uranium, and consequently was impractical to build and use. The paper was pivotal in igniting the interest of first the British and later the American authorities in nuclear weapons. He was also responsible for the recruitment of his compatriot Klaus Fuchs to work on Tube Alloys, as the British nuclear weapons project was called, which resulted in Peierls falling under suspicion when Fuchs was exposed as a spy for the Soviet Union in 1950.
After the war, Peierls returned to the University of Birmingham, where he worked until 1963, and then was the Wykeham Professor of Physics and a Fellow of New College at the University of Oxford until he retired in 1974. At Birmingham he worked on nuclear forces, scattering, quantum field theories, collective motion in nuclei, transport theory and statistical mechanics, and was a consultant to the Atomic Energy Research Establishment at Harwell. He received many awards, including a knighthood in 1968, and wrote several books including Quantum Theory of Solids, The Laws of Nature, Surprises in Theoretical Physics, More Surprises in Theoretical Physics and an autobiography, Bird of Passage. Concerned with the nuclear weapons he had helped to unleash, he worked on the Bulletin of the Atomic Scientists, was President of the Atomic Scientists' Association in the UK, and was involved in the Pugwash movement.
Early life
Rudolf Ernst Peierls was born in the Berlin suburb of Oberschöneweide, the youngest of three children of Heinrich Peierls an electrical engineer, from a family of Jewish merchants. His father was the managing director of a cable factory of Allgemeine Elektricitäts-Gesellschaft, and his mother was his father's first wife, Elisabeth. Rudolf had an older brother, Alfred, and an older sister, Annie. His mother died from Hodgkin's lymphoma in 1921, and his father married Else Hermann, the sister-in-law of the playwright Ludwig Fulda. The family was Jewish, but assimilated, and Peierls and his siblings were baptised as Lutherans. When he came of age, Peierls left the church.Peierls commenced school a year late because he needed glasses, and his parents did not trust him not to lose them or break them. After two years at the local preparatory school, he entered his local gymnasium, the, where he spent the next nine years, passing his abitur examinations in 1925. He wanted to study engineering, but his parents, who doubted his practical abilities, suggested physics instead. He entered the University of Berlin, where he listened to lectures by Max Planck, Walther Bothe and Walther Nernst. Fellow students included Kurt Hirsch and Käte Sperling. The physics laboratory classes were overcrowded, so the first year students were encouraged to take theoretical physics courses instead. Peierls found that he liked the subject.
In 1926 Peierls decided to transfer to the University of Munich to study under Arnold Sommerfeld, who was considered to be the greatest teacher of theoretical physics. Fellow students there included Hans Bethe, Hermann Brück and William V. Houston. At the time, the Bohr-Sommerfeld theory was being overturned by the new quantum mechanics of Werner Heisenberg and Paul Dirac. In 1928, Sommerfeld set off on a world tour. On his advice, Peierls moved to the University of Leipzig, where Heisenberg had been appointed to a chair in 1927.
Heisenberg set Peierls a research project on ferromagnetism. It was known that this was caused by the spin of the electrons in the metal aligning; but the reason for this was unknown. Heisenberg suspected that it was caused by a quantum mechanical effect, caused by the Pauli exclusion principle. Peierls was unable to develop the theory, but work on Hall effect was more productive. The anomalous Hall effect could not be explained with the classical theory of metals, and Heisenberg sensed an opportunity to demonstrate that quantum mechanics could explain it. Peierls was able to do so, resulting in his first published paper.
Heisenberg left in 1929 to lecture in America, China, Japan and India, and on his recommendation Peierls moved on to ETH Zurich, where he studied under Wolfgang Pauli. Pauli set him a problem of investigating the vibration of atoms in a crystal lattice. Peierls explored—and named—the phenomenon of umklapp scattering. He submitted this work as his DPhil thesis, Zur kinetischen Theorie der Wärmeleitung in Kristallen, which was accepted by the University of Leipzig in 1929. His theory made specific predictions of the behaviour of metals at very low temperatures, but another twenty years would pass before the techniques were developed to confirm them experimentally.
Early career
Peierls accepted an offer from Pauli to become his assistant in place of Felix Bloch. Lev Landau was there at this time on a scholarship from the government of the Soviet Union, and Peierls and Landau became friends. They collaborated on deriving a series of wave equations similar to the Schrödinger equation for photons. Unfortunately, their equations, while complicated, were nonsensical. In 1930, Peierls travelled to the Netherlands to meet Hans Kramers, and to Copenhagen to meet Niels Bohr.In August 1930 Pauli and Peierls attended a physics congress in Odessa and met a young physics graduate, Eugenia Nikolaievna Kannegiesser, who, like Landau, came from Leningrad. Since he did not speak Russian and she did not speak German, they conversed in English. During a subsequent visit by Peierls to lecture in Leningrad they were married on 15 March 1931. However, she had to wait for a passport and exit visa. They finally left for Zürich that summer. They had four children: Gaby Ellen, Ronald Frank, Catherine, and Joanna.
Peierls assisted Egon Orowan in understanding the force required to move a dislocation which would be expanded on by Frank Nabarro and called the Peierls–Nabarro force. In 1929, he studied solid-state physics in Zurich under the tutelage of Heisenberg and Pauli. His early work on quantum physics led to the theory of positive carriers to explain the thermal and electrical conductivity behaviours of semiconductors. He was a pioneer of the concept of "holes" in semiconductors. He established "zones" before Léon Brillouin, despite Brillouin's name being currently attached to the idea, and applied it to phonons. Doing this, he discovered the Boltzmann equations for phonons and the umklapp process. He submitted a paper on the subject for his habilitation, acquiring the right to teach at German universities. Physics Today noted that "His many papers on electrons in metals have now passed so deeply into the literature that it is hard to identify his contribution to conductivity in magnetic fields and to the concept of a hole in the theory of electrons in solids".
Academic in exile
In 1932, Peierls was awarded a Rockefeller Fellowship to study abroad, which he used to study in Rome under Enrico Fermi, and then at the Cavendish Laboratory at the University of Cambridge in England under Ralph H. Fowler. In Rome, Peierls completed two papers on electronic band structure, in which he introduced the Peierls substitution, and derived a general expression for diamagnetism in metals at low temperatures. This provided an explanation of the hitherto mysterious properties of bismuth, in which diamagnetic properties were more pronounced than in other metals.File:Poynting Physics building 2.jpg|thumb|left|The Poynting Physics building at the University of Birmingham. Its mode of construction helped give rise to the phrase "redbrick university".
Due to Adolf Hitler's rise to power in Germany, he elected to not return home in 1933, but to remain in Britain. He declined an offer from Otto Stern of a position at the University of Hamburg. Granted leave to remain in Britain, he worked at the Victoria University of Manchester with funding from the Academic Assistance Council, which had been set up to help academic refugees from Germany and other fascist countries. Most of his immediate family also left Germany; his brother and his family settling in Britain, and his sister and her family, along with his father and stepmother, moved to the United States, where his uncle Siegfried lived.
Peierls collaborated with Bethe on photodisintegration and the statistical mechanics of alloys when challenged by James Chadwick. Their results still serve as the basis for mean-field theories of structural phase changes in complete alloys. Although most of his work continued to be about the electron theory of metals, he also looked at Dirac's hole theory, and co-wrote a paper with Bethe on the neutrino. The University of Manchester awarded him a D.Sc. degree. Moving back to Cambridge, he worked with David Shoenberg at the Mond Laboratory on superconductivity and liquid helium. To allow him to lecture, in accordance with its rules, St John's College, Cambridge, awarded him an ex officio M.A. degree.
In 1936, Mark Oliphant was appointed the professor of physics at the University of Birmingham, and he approached Peierls about a new chair in applied mathematics that he was creating there. Peierls got the job despite competition from Harrie Massey and. The appointment at last gave Peierls a secure, permanent position. His students included Fred Hoyle and P. L. Kapur, a student from India. With Kapur he derived the dispersion formula for nuclear reactions originally given in perturbation theory by Gregory Breit and Eugene Wigner, but now included generalising conditions. This is now known as the Kapur–Peierls derivation. It is still used, but in 1947 Wigner and Leonard Eisenbud developed a more widely used alternative method. In 1938, Peierls paid visits to Copenhagen, where he collaborated with Bohr and George Placzek on a paper on what is now known as the Bohr–Peierls–Placzek relation. The Second World War broke out before it could be published; but drafts were circulated for comment, and it became one of the most cited unpublished papers of all time.