arXiv:0709.0021 · Physical Review A

Methods for producing decoherence-free states and noiseless subsystems using photonic qutrits

C. Allen Bishop, Mark Byrd

Published Jan 14, 2008• 9 citations

Abstract

We outline a proposal for a method of preparing an encoded two-state system (logical qubit) that is immune to collective noise acting on the Hilbert space of the states supporting it. The logical qubit is comprised of three photonic three-state systems (qutrits) and is generated by the process of spontaneous parametric down conversion. The states are constructed using linear optical elements along with three down-conversion sources, and are deemed successful by the simultaneous detection of six events. We also show how to select a maximally entangled state of two qutrits by similar methods. For this maximally entangled state we describe conditions for the state to be decoherence-free which do not correspond to collective errors.

DOI: 10.1103/physreva.77.012314

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