John Harrison Watrous is a professor of computer science at the

David R. Cheriton School of Computer Science The David R. Cheriton School of Computer Science is a professional school within the Faculty of Mathematics at the University of WaterlooQS World University Rankingsranked the David R. Cheriton School of Computer Science 24th in the world, 10th ...

at the University of Waterloo, a member of the Institute for Quantum Computing, an affiliate member of the Perimeter Institute for Theoretical Physics and a Fellow of the Canadian Institute for Advanced Research.John Watrous
at the Canadian Institute for Advanced Research website. He was a faculty member in the Department of Computer Science at the University of Calgary from 2002 to 2006 where he held a Canada Research Chair in

quantum computing Quantum computing is a type of computation whose operations can harness the phenomena of quantum mechanics, such as superposition, interference, and entanglement. Devices that perform quantum computations are known as quantum computers. Though ...

. He is an editor of the journal

Theory of Computing ''Theory of Computing'' is a peer-reviewed open access scientific journal covering theoretical computer science. The journal was established in 2005 and is published by the Department of Computer Science of the University of Chicago. The edit ...

and former editor for the journal ''

Quantum Information & Computation In physics, a quantum (plural quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a physical property can be "quantized" is referred to as "the hypothesis of quantizati ...

''. His research interests include quantum information and

quantum computation Quantum computing is a type of computation whose operations can harness the phenomena of quantum mechanics, such as superposition, interference, and entanglement. Devices that perform quantum computations are known as quantum computers. Though ...

. He is well known for his work on quantum interactive proofs, and the quantum analogue of the celebrated result IP equals PSPACE, QIP equals PSPACE. This was preceded by a series of results, showing QIP can be constrained to 3 messages, QIP is contained in EXP, and the 2-message version of QIP is in PSPACE. He has also published important papers on quantum finite automata and quantum cellular automata. With Scott Aaronson, he showed that certain forms of time travel can make quantum and classical computation equivalent: together, the authors showed that quantum effects do not offer advantages for computation if computers can send information to the past through a type of closed timelike curve proposed by the physicist David Deutsch. He obtained his Ph.D. in 1998 at the University of Wisconsin–Madison under the supervision of

Eric Bach Eric Bach is an American computer scientist who has made contributions to computational number theory. Bach completed his undergraduate studies at the University of Michigan, Ann Arbor, and got his Ph.D. in computer science from the University o ...

..John Watrous
at the Institute for Quantum Computing directory.

References

{{DEFAULTSORT:Watrous, John Living people University of Waterloo faculty University of Wisconsin–Madison alumni Theoretical computer scientists Cellular automatists Canada Research Chairs Year of birth missing (living people) Quantum information scientists