We present the theoretical basis for and experimental verification of arbitrary single-qubit state generation, using the polarization of photons generated via spontaneous parametric downconversion. Our precision measurement and state reconstruction system has the capability to distinguish over 3 million states, all of which can be reproducibly generated using our state creation apparatus. In order to complete the triumvirate of single qubit control, there must be a way to not only manipulate single qubits after creation and before measurement, but a way to characterize the manipulations \emph{themselves}. We present a general representation of arbitrary processes, and experimental techniques for generating a variety of single qubit manipulations, including unitary, decohering, and (partially) polarizing operations.
@article{arxiv.quant-ph/0502177,
title = {Precise Creation, Characterization, and Manipulation of Single Optical Qubits},
author = {Nicholas Peters and Joseph Altepeter and Evan Jeffrey and David Branning and Paul Kwiat},
journal= {arXiv preprint arXiv:quant-ph/0502177},
year = {2007}
}