Note on purifications of a qubit
Abstract
This work provides a parametrization of the set of purifications of a 2x2 mixed state, and joint purifications (if any) of a given pair of mixed 2x2 states. The former is parametrized by SO(3, R), while the latter is parametrized by SO(2,R), except when the 2x2 state is pure. Using this parametrization some quantum information measures are obtained. In the process it is shown how to solve one variation of the classical Procustes problem. The appendix is devoted to the first step in extending this work to higher dimensions.
Keywords
Cite
@article{arxiv.quant-ph/0210091,
title = {Note on purifications of a qubit},
author = {Tiberiu Constantinescu and Viswanath Ramakrishna},
journal= {arXiv preprint arXiv:quant-ph/0210091},
year = {2007}
}
Comments
Some of the results were presented at CRM Quantum Control Conference from October 6th-11th 2002. 14 pages long. Manuscript originally scheduled for October 8th, 2002 on this site, but did not due to illegibility of the pdf version. Current replacement was intended to render the title in the text of the manuscript agree with the title as it appears in the announcement. There are no other changes