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
Doctoral Advisor	Léon Brillouin and Wendell Furry
Doctoral 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. Image File history File links Rolf_landauer. ... February 4 is the 35th day of the year in the Gregorian Calendar. ... 1927 (MCMXXVII) was a common year starting on Saturday (link will take you to calendar). ... Stuttgart [], a city located in southern Germany, is the capital of the state of Baden-Württemberg with a population of approximately 590,000 (as of September 2005) in the city and around 3 million in the metropolitan area. ... April 27 is the 117th day of the year (118th in leap years) in the Gregorian Calendar, with 248 days remaining. ... 1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Older Persons by the United Nations. ... Briarcliff Manor is a village located in Westchester County, New York. ... Official language(s) English de facto Capital Albany Largest city New York City Area  Ranked 27th  - Total 54,520 sq mi (141,205 km²)  - Width 285 miles (455 km)  - Length 330 miles (530 km)  - % water 13. ... Image File history File links Flag_of_the_United_States. ... Image File history File links Flag_of_the_United_States. ... Image File history File links Flag_of_Germany. ... Physicists working in a government lab A physicist is a scientist who studies or practices physics. ... NASA logo Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... now. ... Harvard University is a private university in Cambridge, Massachusetts, USA, and a member of the Ivy League. ... Léon N. Brillouin (August 7, 1889-1969) was a French physicist. ... Landauers Principle, first argued in 1961 by Rolf Landauer of IBM, holds that any logically irreversible manipulation of information, such as the erasure of a bit or the merging of two computation paths, must be accompanied by a corresponding entropy increase in non-information bearing degrees of freedom of... There are very few or no other articles that link to this one. ... 1927 (MCMXXVII) was a common year starting on Saturday (link will take you to calendar). ... 1999 (MCMXCIX) was a common year starting on Friday, and was designated the International Year of Older Persons by the United Nations. ... now. ... Physicists working in a government lab A physicist is a scientist who studies or practices physics. ... 1961 (MCMLXI) was a common year starting on Sunday (the link is to a full 1961 calendar). ... Information as a concept bears a diversity of meanings, from everyday usage to technical settings. ... An irreversible circuit is a circuit whose inputs cannot be reconstructed from its outputs. ... In thermodynamics, entropy, symbolized by S, is a state function of a thermodynamic system defined by the differential quantity , where dQ is the amount of heat absorbed in a reversible process in which the system goes from the one state to another, and T is the absolute temperature. ... In physics, heat, symbolized by Q, is defined as energy in transit. ... The term reversible computing refers to any computational process that is (at least to some close approximation) reversible, i. ... In quantum mechanics, quantum information is physical information that is held in the state of a quantum system. ... Molecule of alanine used in NMR implementation of error correction. ...

Landauer was born in 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 1935. Following service in the US Navy as an Electrician's Mate, Landauer earned his Ph.D. from Harvard in 1950. Stuyvesant High School, commonly known as Stuy, is a New York City public high school that specializes in math and science. ...

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. NASA logo Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ...

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.

Landauer was born on 4 February 1927 in Stuttgart, Germany. He arrived in the U.S. in 1938, at the age of 11, and received his undergraduate degree from Harvard University just seven years later. Following graduation, he served in the U.S. Navy as an Electronics Technician's Mate and received a Ph.D. from Harvard in 1950.

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 passed away on 27 April 1999 at his home in Briarcliff Manor, NY, USA. He died at the age of 72 from brain cancer.

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Honours

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

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External Links

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

References

• 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