title: Demonstration of unconditional one-way quantum computations for continuous variables.
abstract: One-way quantum computation is a very promising candidate to fulfill the capabilities of quantum information processing. Here we demonstrate an important set of unitary operations for continuous variables using a linear cluster state of four entangled optical modes. These operations are performed in a fully measurement-controlled and completely unconditional fashion. We implement three different levels of squeezing operations and a Fourier transformation, all of which are accessible by selecting the correct quadrature measurement angles of the homodyne detections. Though not sufficient, these linear transformations are necessary for universal quantum computation.
authors.affiliation: Department of Applied Physics, School of Engineering, The University of Tokyo, Tokyo, Japan.
authors.forename: Ryuji
authors.initials: R
authors.lastname: Ukai
authors.forename: Noriaki
authors.initials: N
authors.lastname: Iwata
authors.forename: Yuji
authors.initials: Y
authors.lastname: Shimokawa
authors.forename: Seiji C
authors.initials: SC
authors.lastname: Armstrong
authors.forename: Alberto
authors.initials: A
authors.lastname: Politi
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Yoshikawa
authors.forename: Peter
authors.initials: P
authors.lastname: van Loock
authors.forename: Akira
authors.initials: A
authors.lastname: Furusawa