Charles H. Bennett (computer scientist)
Encyclopedia
Charles H. Bennett is an IBM Fellow
at IBM Research
. Bennett's recent work at IBM has concentrated on a re-examination of the physical basis of information, applying quantum physics to the problems surrounding information exchange. He has played a major role in elucidating the interconnections between physics and information, particularly in the realm of quantum computation, but also in cellular automata and reversible computing
. He discovered, with Gilles Brassard
, the concept of quantum cryptography
and is one of the founding fathers of modern quantum information theory.
Born in 1943 in New York City, he earned a B.S. in Chemistry from Brandeis University
in 1964, and received his PhD from Harvard in 1970 for molecular dynamics studies (computer simulation of molecular motion) under David Turnbull
and Berni Alder
. For the next two years he continued this research under the late Aneesur Rahman
at Argonne Laboratory.
After joining IBM Research in 1972, he built on the work of IBM's Rolf Landauer
to show that general-purpose computation can be performed by a logically and thermodynamically reversible apparatus; and in 1982 he proposed a re-interpretation of Maxwell's demon
, attributing its inability to break the second law to the thermodynamic
cost of destroying, rather than acquiring, information. He also published an important paper on the estimation of free energy differences between two systems, the Bennett acceptance ratio
method.
In collaboration with Gilles Brassard
of the Université de Montréal
he developed a practical system of quantum cryptography
, known as BB84
, which allows secure communication between parties who share no secret information initially, based on the uncertainty principle. With the help of John Smolin
, he built the world's first working demonstration of quantum cryptography in 1989.
His other research interests include algorithmic information theory
, in which the concepts of information and randomness are developed in terms of the input/output relation of universal computers, and the analogous use of universal computers to define the intrinsic complexity or "logical depth" of a physical state as the time required by a universal computer to simulate the evolution of the state from a random initial state.
In 1993 Bennett and Brassard, in collaboration with others, discovered "quantum teleportation
", an effect in which the complete information in an unknown quantum state is decomposed into purely classical information and purely non-classical Einstein-Podolsky-Rosen (EPR paradox
) correlations, sent through two separate channels, and later reassembled in a new location to produce an exact replica of the original quantum state that was destroyed in the sending process.
In 1995-7, working with Smolin
, Wootters
, IBM's DiVincenzo, and other collaborators, he introduced several techniques for faithful transmission of classical and quantum information through noisy channels, part of the larger and recently very active field of quantum information and computation theory.
Bennett is a Fellow of the American Physical Society and a member of the National Academy of Sciences. He was awarded the 2008 Harvey Prize
by the Technion and the 2006 Rank Prize in opto-electronics.
IBM Fellow
An IBM Fellow is an appointed position at IBM made by IBM’s CEO. Typically only 4 to 9 IBM Fellows are appointed each year, at the annual Corporate Technical Recognition Event in May or June. It is the highest honor a scientist, engineer, or programmer at IBM can achieve.The IBM Fellows program...
at IBM Research
IBM Research
IBM Research, a division of IBM, is a research and advanced development organization and currently consists of eight locations throughout the world and hundreds of projects....
. Bennett's recent work at IBM has concentrated on a re-examination of the physical basis of information, applying quantum physics to the problems surrounding information exchange. He has played a major role in elucidating the interconnections between physics and information, particularly in the realm of quantum computation, but also in cellular automata and reversible computing
Reversible computing
Reversible computing is a model of computing where the computational process to some extent is reversible, i.e., time-invertible. A necessary condition for reversibility of a computational model is that the transition function mapping states to their successors at a given later time should be...
. He discovered, with Gilles Brassard
Gilles Brassard
Gilles Brassard was born in Montreal, Canada, in 1955. He received a Masters degree from the Université de Montréal in 1975, and obtained his Ph.D. in Computer Science from Cornell University in 1979, working in the field of cryptography with John Hopcroft as his advisor...
, the concept of quantum cryptography
Quantum cryptography
Quantum key distribution uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages...
and is one of the founding fathers of modern quantum information theory.
Born in 1943 in New York City, he earned a B.S. in Chemistry from Brandeis University
Brandeis University
Brandeis University is an American private research university with a liberal arts focus. It is located in the southwestern corner of Waltham, Massachusetts, nine miles west of Boston. The University has an enrollment of approximately 3,200 undergraduate and 2,100 graduate students. In 2011, it...
in 1964, and received his PhD from Harvard in 1970 for molecular dynamics studies (computer simulation of molecular motion) under David Turnbull
David Turnbull (materials scientist)
David Turnbull was an American physical chemist who worked in the interdisciplinary fields of materials science and applied physics. Turnbull made seminal contribution to solidification theory and glass formation. Turnbull was born in Elmira, Elmira Township, Stark County, Illinois...
and Berni Alder
Berni Alder
Berni Julian Alder is an American physicist specialized in statistical mechanics, and a pioneer of numerical simulation in physics.- Career :Alder was born as a Swiss citizen in Germany...
. For the next two years he continued this research under the late Aneesur Rahman
Aneesur Rahman
Aneesur Rahman pioneered the application of computational methods to physical systems. His 1964 paperon liquid argon studied a system of 864 argon atoms on a CDC 3600 computer, utilizing a Lennard-Jones potential. His algorithms still form the basis for many codes written today...
at Argonne Laboratory.
After joining IBM Research in 1972, he built on the work of IBM's Rolf Landauer
Rolf Landauer
Rolf William Landauer was an IBM physicist who in 1961 argued that when information is lost in an irreversible circuit, the information becomes entropy and an associated amount of energy is dissipated as heat...
to show that general-purpose computation can be performed by a logically and thermodynamically reversible apparatus; and in 1982 he proposed a re-interpretation of Maxwell's demon
Maxwell's demon
In the philosophy of thermal and statistical physics, Maxwell's demon is a thought experiment created by the Scottish physicist James Clerk Maxwell to "show that the Second Law of Thermodynamics has only a statistical certainty." It demonstrates Maxwell's point by hypothetically describing how to...
, attributing its inability to break the second law to the thermodynamic
Thermodynamics
Thermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation...
cost of destroying, rather than acquiring, information. He also published an important paper on the estimation of free energy differences between two systems, the Bennett acceptance ratio
Bennett acceptance ratio
The Bennett acceptance ratio method is an algorithm for estimating the difference in free energy between two systems .It was suggested by Charles H. Bennett in 1976....
method.
In collaboration with Gilles Brassard
Gilles Brassard
Gilles Brassard was born in Montreal, Canada, in 1955. He received a Masters degree from the Université de Montréal in 1975, and obtained his Ph.D. in Computer Science from Cornell University in 1979, working in the field of cryptography with John Hopcroft as his advisor...
of the Université de Montréal
Université de Montréal
The Université de Montréal is a public francophone research university in Montreal, Quebec, Canada. It comprises thirteen faculties, more than sixty departments and two affiliated schools: the École Polytechnique and HEC Montréal...
he developed a practical system of quantum cryptography
Quantum cryptography
Quantum key distribution uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages...
, known as BB84
BB84
BB84 is a quantum key distribution scheme developed by Charles Bennett and Gilles Brassard in 1984. It is the first quantum cryptography protocol. The protocol is provably secure, relying on the quantum property that information gain is only possible at the expense of disturbing the signal if the...
, which allows secure communication between parties who share no secret information initially, based on the uncertainty principle. With the help of John Smolin
John A. Smolin
John A. Smolin is an American physicist at IBM's Thomas J. Watson Research Center.Smolin is best known for his work in quantum information theory, where, with collaborators, he introduced several important techniques, including entanglement distillation, for quantum error-correction and the...
, he built the world's first working demonstration of quantum cryptography in 1989.
His other research interests include algorithmic information theory
Algorithmic information theory
Algorithmic information theory is a subfield of information theory and computer science that concerns itself with the relationship between computation and information...
, in which the concepts of information and randomness are developed in terms of the input/output relation of universal computers, and the analogous use of universal computers to define the intrinsic complexity or "logical depth" of a physical state as the time required by a universal computer to simulate the evolution of the state from a random initial state.
In 1993 Bennett and Brassard, in collaboration with others, discovered "quantum teleportation
Quantum teleportation
Quantum teleportation, or entanglement-assisted teleportation, is a process by which a qubit can be transmitted exactly from one location to another, without the qubit being transmitted through the intervening space...
", an effect in which the complete information in an unknown quantum state is decomposed into purely classical information and purely non-classical Einstein-Podolsky-Rosen (EPR paradox
EPR paradox
The EPR paradox is a topic in quantum physics and the philosophy of science concerning the measurement and description of microscopic systems by the methods of quantum physics...
) correlations, sent through two separate channels, and later reassembled in a new location to produce an exact replica of the original quantum state that was destroyed in the sending process.
In 1995-7, working with Smolin
John A. Smolin
John A. Smolin is an American physicist at IBM's Thomas J. Watson Research Center.Smolin is best known for his work in quantum information theory, where, with collaborators, he introduced several important techniques, including entanglement distillation, for quantum error-correction and the...
, Wootters
William Wootters
William Kent Wootters is an American physicist, and a leading contributor to the field of quantum information theory. He proved the no cloning theorem in a joint paper with Wojciech H. Zurek. It was also independently discovered by Dennis Dieks. He has also worked on the quantification of...
, IBM's DiVincenzo, and other collaborators, he introduced several techniques for faithful transmission of classical and quantum information through noisy channels, part of the larger and recently very active field of quantum information and computation theory.
Bennett is a Fellow of the American Physical Society and a member of the National Academy of Sciences. He was awarded the 2008 Harvey Prize
Harvey Prize
The Harvey Prize is awarded by the Technion in Haifa, Israel. It is awarded in different disciplines of Science, Technology, Human Health, and Contributions to Peace in the Middle East. Two awards - each of $75,000 - are given away annually...
by the Technion and the 2006 Rank Prize in opto-electronics.