arXiv:1108.4909 · Physical Review A
Strategies for measurement-based quantum computation with cluster states transformed by stochastic local operations and classical communication
Adam G. D’Souza, David L. Feder
Abstract
We examine cluster states transformed by stochastic local operations and classical communication, as a resource for deterministic universal computation driven strictly by projective measurements. We identify circumstances under which such states in one dimension constitute resources for random-length single-qubit rotations, in one case quasideterministically ($N\ensuremath{-}U\ensuremath{-}N$ states) and in another probabilistically ($B\ensuremath{-}U\ensuremath{-}B$ states). In contrast to the cluster states, the $N\ensuremath{-}U\ensuremath{-}N$ states exhibit spin correlation functions that decay exponentially with distance, while the $B\ensuremath{-}U\ensuremath{-}B$ states can be arbitrarily locally pure. A two-dimensional square $N\ensuremath{-}U\ensuremath{-}N$ lattice is a universal resource for quasideterministic measurement-based quantum computation. Measurements on cubic $B\ensuremath{-}U\ensuremath{-}B$ states yield two-dimensional cluster states with bond defects, whose connectivity exceeds the percolation threshold for a critical value of the local purity.