2002/02/28 by Luis L. Sanchez-Soto, L. L. Sánchez-Soto, Julián Delgado +5
Computer Science · Physics and Astronomy · #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1103/physreva.66.042112
published as Phys. Rev. A 66, 042112 (2002) · 11 pages, previous title has changed, new section added, corrected typos, no figures
arxiv created 2002/08/06 · openalex publication_date 2002/10/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We explore the role played by the phase in an accurate description of the entanglement of bipartite systems. We first present an appropriate polar decomposition that leads to a truly Hermitian operator for the phase of a single qubit. We also examine the positive operator-valued measures that can describe the qubit phase properties. When dealing with two qubits, the relative phase seems to be a natural variable to understand entanglement. In this spirit, we propose a measure of entanglement based on this variable.