Our article, Cluster-State Quantum Computing Enhanced by High-Fidelity Generalized Measurements, was published in Physical Review Letters. This work was done with Terry Rudolph at Imperial College and Gregor Weihs at the University of Innsbruck.
We introduce and implement a technique to extend the quantum computational power of cluster states by replacing some projective measurements with generalized quantum measurements (POVMs). As an experimental demonstration we fully realize an arbitrary three-qubit cluster computation by implementing a tunable linear-optical POVM, as well as fast active feedforward, on a two-qubit photonic cluster state. Over 206 different computations, the average output fidelity is 0.9832±0.0002; furthermore the error contribution from our POVM device and feedforward is only of O(