Preparation of pure and mixed polarization qubits and the direct measurement of figures of merit
arXiv:quant-ph/0606191 · doi:10.1103/PhysRevA.75.012104
Abstract
Non-classical joint measurements can hugely improve the efficiency with which certain figures of merit of quantum systems are measured. We use such a measurement to determine a particular figure of merit, the purity, for a polarization qubit. In the process we highlight some of subtleties involved in common methods for generating decoherence in quantum optics.
5 pages, 3 figures, 1 table