Using a spontaneous parametric-downconversion source of photon pairs, we are working towards the creation of arbitrary 2-qubit quantum states with high fidelity. Currently, all physically allowable combinations of polarization entanglement and mixture can be produced, including maximally-entangled mixed states. The states are experimentally measured and refined via computer-automated quantum-state tomography, and this system has also been used to perform single-qubit and ancilla-assisted quantum process tomography.
@article{arxiv.quant-ph/0303040,
title = {Taming Entanglement},
author = {Paul Kwiat and Joe Altepeter and David Branning and Evan Jeffrey and Nicholas Peters and Tzu-Chieh Wei},
journal= {arXiv preprint arXiv:quant-ph/0303040},
year = {2007}
}
Comments
7 pages, 5 Figures. To appear in the Proceedings of the 6th International Conference on Quauntum Communication, Measurement and Computing