Bennett, Charles (physicist)

Charles Bennett was born in 1943 in New York . His parents, Ann and Boyd Bennett, were music teachers.

In 1960, he graduated from high school in New York ( ) and enrolled at Brandeis University ^[2] in Waltham ^[2] . There he studied chemistry for 4 years and in 1964 received a bachelor of science degree in chemistry. After that, in 1964, Bennett entered Harvard University and began to study molecular dynamics under the leadership of David Turnbull and . In 1971, he received his Ph.D. in computer simulation of molecular motion. Then Bennett continued research already under the direction of in the Argonne National Laboratory and was engaged in it for another year ^[3] .

In 1972, Charles Bennett joined IBM Research. At the same time, another physicist, was engaged in problems related to theoretical computer science at IBM Research. This had a profound effect on Bennett, the future founder of quantum computer science , and his interests related to physics and computer science were formed ^[3] .

In 1973, Charles Bennett published an article on the logical reversibility of computations ^[4] , in which, based on the work of Rolf Landauer, he showed that computations can be performed in a reversible way. To some extent, he foresaw the main idea of ​​quantum computers - the reversibility of computing ^[3] .

In 1982, Charles Bennett, relying on information theory , proposed yet another interpretation of Demon Maxwell , which shows that a finite amount of memory will necessarily lead to the destruction of information, which in turn is a thermodynamically irreversible process ^[5] . He also proposed an algorithm for calculating the difference of free energies of the two systems, which was called the method ^[6] .

From 1983 to 1985, Charles Bennett lectured in cryptography and computational physics at Boston University ^[3] .

In 1984, Charles Bennett, together with Gilles Brassard of the University of Montreal , proposed the first quantum information encryption protocol BB84 , based on the Heisenberg uncertainty principle . While most traditional methods are based on the computational complexity of algorithms, for example, factorization . Bennett suggested sending one, randomly polarized, photon to each of the interlocutors. Thus, you can establish a secure connection between the interlocutors without the initial secret information. Subsequently, together with , he created the first quantum key generator. After that, the rapid development of quantum cryptography using optical fiber and in free space began ^{[2] [3]} .

In parallel with his research on quantum cryptography, Charles Bennett contributed to the development of the algorithmic theory of information . He introduced another definition of the measure of internal complexity of a physical state ( ), different from the definition of a measure of complexity according to Kolmogorov ^[3] .

In the early 1990s, Charles Bennett became interested in the unusual relationships of quantum states discovered in the 1930s by Einstein , Podolsky , Rosen, and Schrödinger , which are called quantum entanglement . In 1992, in collaboration with , Bennett published an article that revolutionized communication theory. The article said that using one quantum bit (for example, a photon with two polarizations ), thanks to a pair of "entangled" quantum particles, it becomes possible to send two bits of information. This allows you to bypass the Holevo border , according to which one quantum bit can transmit only one bit of information. The phenomenon is called quantum superdense coding ^[3] .

The same year, William Wutters' seminar was held in Montreal . It hotly discussed the problems associated with the optimal transfer of the quantum state between two laboratories located far from each other. The discussion was attended by , , and Gilles Brassard . Perez mentioned that on the occasion of his 50th birthday, Bennett asked a fundamental question: “What happens if we give each laboratory one particle out of a pair of entangled ones?” This idea served as the basis for the discovery of the phenomenon of quantum teleportation .

In 1993, the Physical Review Letters published an article entitled Teleporting an Unknown Quantum State via Dual Classical and Einstein-Podolsky-Rosen Channels ^[7] , which was written by the participants in the Montreal discussion. In the article, scientists showed that having in each laboratory a pair of entangled particles, as well as the ability to exchange two bits of information, it is possible to transfer quantum information from the first particle to the second, which is located in a remote laboratory. Quantum information is erased from the first particle and then restored to the second due to their entanglement. Several years later, both quantum superdense coding and quantum teleportation were verified experimentally. The experiments were conducted by the team of Anton Zeilinger ^[3] .

In 1995-97, Charles Bennett and his team created a quantum theory of entanglement and proposed several different techniques for stably transmitting classical and quantum information over a noisy channel. As a result, together with the discovery of quantum teleportation and quantum superdense coding, the scientist made a huge contribution to the theory of quantum communication and quantum computing. In particular, a protocol based on the phenomenon of quantum entanglement and developed by Bennett and his colleagues inspired a team of scientists from Gdansk . Namely, in 1996, the so-called confusion limit was opened in Gdansk. This has generated interest among other scientists, which led, among other things, to the discovery of the so-called information blocking effect and also to the creation of the basis for constructing the theory of quantum many-particle interaction ^[3] .

Charles Bennett made an enormous contribution to quantum channel theory. In particular, his article on the relationship between the bandwidth of a quantum channel due to entanglement and Shannon's inverse theorem, which has become the main one in this direction of science ^{[3] [8]} .

The achievements of Charles Bennett formed the foundation for a new direction of science - the quantum theory of information . They helped the rapid development of experimental techniques for transforming and controlling quantum systems , i.e., quantum technologies . They also introduced revolutionary changes to the basis of the quantum description of nature ^[3] .

Charles Bennett is the author and co-author of articles that are currently cited more than 28,300 times, including 10 articles cited more than 1,000 times. His work on quantum teleportation has been cited more than 7,000 times ^[3] .

Charles Bennett is married and has three grown children. His main hobbies are photography and music ^[3] .

• International Quantum Communication Award (1996) ^[9]
• Rank Award (2006) ^[10]
• Harvey Award (2008) ^[1]
• Okava Prize (2010)
• Thomson Reuters Citation Laureates (2012) ^[11]
• Member of the US National Academy of Sciences (1997) ^[12]
• Honorary Doctor of the University of Gdansk (2006) ^[3]
• IBM Fellow ^[3]
• Fellow of the American Physical Society ^[3]