We experimentally demonstrate a programmable quantum gate that applies a sign flip operation to data qubit in an arbitrary basis fully specified by the quantum state of a two-qubit program register. Our linear-optical implementation is inspired by teleportation-based schemes for quantum computing and relies on multiphoton interference and coincidence detection. We confirm the programmability of the gate and its high-fidelity performance by carrying out full quantum process tomography of the resulting operation on data qubit for several different programs.
@article{arxiv.0905.4050,
title = {Experimental demonstration of teleportation-based programmable quantum gate},
author = {Lukas Slodicka and Miroslav Jezek and Jaromir Fiurasek},
journal= {arXiv preprint arXiv:0905.4050},
year = {2009}
}