Leonard Mandel

Leonard Mandel ( May 9, 1927 in Berlin, † February 9, 2001 in Pittsford, New York ) was a British- American physicist and one of the pioneers of quantum optics.

Life

Mandel was a teenager on by his talent on the violin. With his parents he fled from the Nazis from Berlin to England. He was also there in the school by his talent in physics, but could not get a scholarship to the University of Cambridge, as he was not a British citizen at the time. Mandel made ​​1947 his bachelor's degree in mathematics and physics at Birkbeck College, University of London, where he worked during the day and only in the evening attended the University. In 1951 he completed his doctorate there with Paul George about cosmic radiation ( Interactions of non ionizing cosmic ray particles ), where he hired measurements in the Alps. From 1951 to 1954 he was a scientist at Imperial Chemical Industries in Welwyn Garden City and then to 1964 Lecturer at Imperial College in London before ( at the invitation of his colleague Emil Wolf, whom he knew from England) professor at the University of Rochester was, 1994 DuBridge as Lee Professor of Physics and Optics.

Since 2001 he was a member of the National Academy of Sciences and is a member of the American Academy of Arts and Sciences and the New York Academy of Sciences. In 1993 he received the Frederic Ives Medal and in 1994 the Young Medal. In addition, he was awarded the Max Born Award of the Optical Society of America and the Italian Marconi medal.

His ( 39 ) H. Jeff Kimble and graduate students include Zhe - Yu Ou.

He was married in 1953 (his wife Jeanne studied with him physics and was a ballet teacher ) and had a daughter and a son.

Work

Mandel made ​​fundamental contributions to the photon statistics. He came to quantum optics, to the analysis (1958 /59) of the Hanbury Brown - Twiss effect ( by Robert Hanbury Brown and Richard Twiss 1956), from which his almond formula originated in the photon statistics. With his staff, he was the first to show the interference of a photon with itself ( with his student R. Pfleegor 1967 ) using the investigation of the 4th order interference, a technique which he developed it.

Almond also demonstrated with his students, H. Jeff Kimble and M. Dagenais first photon antibunching 1977 (regardless of HJ Carmichael and DF Walls predicted ) in the emission of a single atom, which follows a non- classical statistics and represents a signature for quantum behavior.

He also examined the early laser - phase transition, which became one of his main areas of research.

Almond is also known in particular for quantum optical experiments on the foundations of quantum mechanics. With SR Friberg and CK Hong He Showed off the non-classical character of the " Parametric Down Conversion Process" (PDC ) for generating a correlated photon pair in optically nonlinear crystals and demonstrated a localized one-photon state. They also demonstrated the first quantum cryptography with a pair of correlated photons. With Hong and Zhe - Yu Ou, he led the Hong - Ou - Mandel interferometer and Hong - Ou -Mandel interference ( HOMI ), where they demonstrated the Hong - Ou -Mandel effect, place the application in experiments on quantum computers. With Ou he demonstrated the violation of Bell inequalities on a pair of correlated photons generated by downconversion. As a result, he examined other examples of quantum entanglement, and in 1991 they demonstrated those discussed in 1982 by Marlan Scully quantum eraser (1991, with LJ Wang, XY Zou ). With D. Branning, J. Torgerson, C. Monken, he showed experimentally directly one of the paradoxical predictions of quantum mechanics that there is no reality without measurement ( violation of the assumption of local realism, as the discussion of the EPR experiment by Einstein, Rosen, Podolsky is based ).

Writings

• With Emil Wolf: Optical coherence and quantum optics. Cambridge University Press, 1995.
• Wolf: Coherence properties of optical fields. In: Reviews of Modern Physics. Bd.37, 1965, p 231 ( review of their work by Mandel, Wolf in Science Citation Classics, pdf file).
• Quantum effects in one photon and two photon interference. In: Reviews of Modern Physics. Vol 71, 1999, p 274