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Rolf Landauer

Rolf William Landauer
Born	February 4, 1927 Stuttgart, Germany
Died	April 27, 1999 Briarcliff Manor, New York, USA
Residence	USA
Nationality	American -German
Field	Physicist
Institution	National Advisory Committee for Aeronautics IBM
Alma mater	Harvard
Academic advisor	Léon Brillouin and Wendell Furry
Notable students	None
Known for	Landauer's principle
Notable prizes	Oliver E. Buckley Prize (1995)

Rolf Landauer (1927 – 1999) was an IBM physicist who in 1961 demonstrated that when information is lost in an irreversible circuit, the information becomes entropy and an associated amount of energy is dissipated as heat. This principle is relevant to reversible computing, quantum information and quantum computing.

Landauer was born on February 4, 1927 in Stuttgart, Germany. Of Jewish parentage, he immigrated to the United States in 1938, graduated in 1943 from Stuyvesant High School, one of New York City's mathematics and science magnet schools, and obtained his undergraduate degree from Harvard in 1945. Following service in the US Navy as an Electrician's Mate, Landauer earned his Ph.D. from Harvard in 1950.

He first worked for two years at NASA, then known as the National Advisory Committee for Aeronautics, then at the age of 25, Landauer began a career in semiconductors at IBM. As part of the two-man team responsible for managing IBM's Research Division in the mid-1960s, he played a key role in the creation of a number of programs, including the company's work on semiconductor lasers. In 1969, Landauer was appointed an IBM Fellow.

Much of his research since then relates to the kinetics of small structures. He showed that in systems with two or more competing states of local stability, their likelihood depends on noise all along the path connecting them. In electron transport theory, he is particularly associated with the idea, taken from circuit theory, that electric flow can be considered a consequence of current sources as well as applied fields. He has also pioneered in the area of information handling. His principles have been applied to computers and to the measurement process, and is the basis for Landauer's own demonstration that communication, in principle, can be done without minimal unavoidable energy use.

A Life Fellow of the IEEE, Dr. Landauer is a member of the National Academy of Engineering, the National Academy of Sciences, the European Academy of Science and the Arts and a Fellow of The American Academy of Arts and Sciences. He has an honorary doctorate from the Technion in Israel and was the 1991 Scott Lecturer at the Cavendish Laboratory at Cambridge University. He was awarded the 1992 Stuart Ballantine Medal of the Franklin Institute, the Centennial Medal by Harvard in 1993, the Oliver E. Buckley Prize by the American Physical Society in 1995, the Moet Hennessey Louis Vuitton (LVMH) Science for Art Prize in 1997, and the IEEE Edison Medal in 1998 'For pioneering contributions to the physics of computing and conduction.'

The range of his work has been recognized in special issues of two journals, 10 years apart. They are the IBM Journal of Research and Development (January 1988) and the Superlattices and Microstructures (March/April 1998). Dr. Landauer on 27 April 1999 at his home in Briarcliff Manor, NY, USA from brain cancer.

• spouse = Muriel
• children = Karen, Carl & Tom

• Stuart Ballantine Medal (1992)
• Harvard Centennial Medal (1993)
• Oliver E. Buckley Prize (1995)
• IEEE Edison Medal (1998)

• Web page at IEEE
• Stuyvesant math team
• PhysicsWeb Obituary
• Nature Obituary
• Jewish Computer Scientists

• Perry, R. T. (2004). The temple of quantum computing. p. 26 – 27. Retrieved 11 January 2005 with http://home.swiftdsl.com.au/~chillers/TOQCv1_0.pdf