title: Pseudo-random unitary operators for quantum information processing.
abstract: In close analogy to the fundamental role of random numbers in classical information theory, random operators are a basic component of quantum information theory. Unfortunately, the implementation of random unitary operators on a quantum processor is exponentially hard. Here we introduce a method for generating pseudo-random unitary operators that can reproduce those statistical properties of random unitary operators most relevant to quantum information tasks. This method requires exponentially fewer resources, and hence enables the practical application of random unitary operators in quantum communication and information processing protocols. Using a nuclear magnetic resonance quantum processor, we were able to realize pseudorandom unitary operators that reproduce the expected random distribution of matrix elements.
authors.affiliation: Department of Nuclear Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. jemerson@perimeterinstitute.ca
authors.forename: Joseph
authors.initials: J
authors.lastname: Emerson
authors.forename: Yaakov S
authors.initials: YS
authors.lastname: Weinstein
authors.forename: Marcos
authors.initials: M
authors.lastname: Saraceno
authors.forename: Seth
authors.initials: S
authors.lastname: Lloyd
authors.forename: David G
authors.initials: DG
authors.lastname: Cory