2005/11/08 by Thomas F. Jordan, Anil Shaji, E. C. G. Sudarshan · 5 citations
Computer Science · Physics and Astronomy · #Noncommutative and Quantum Gravity Theories #Quantum Information and Cryptography #Quantum Mechanics and Applications #quant-ph
paper · pdf · doi:10.1103/physreva.73.032104
published as Phys.Rev.A73:032104,2006 · 7 Pages, 3 Figures
arxiv created 2005/11/08 · openalex publication_date 2006/03/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Lorentz transformations of spin density matrices for a particle with positive mass and spin 1∕2 are described by maps of the kind used in open quantum dynamics. They show how the Lorentz transformations of the spin depend on the momentum. Since the spin and momentum generally are not independent, the maps generally are not completely positive and act in limited domains. States with two momentum values are considered, so the maps are for the spin qubit correlated with the qubit made from the two momentum values, and results from the open quantum dynamics of two coupled qubits can be applied. Inverses are used to show that every Lorentz transformation completely removes the spin polarization, and so completely removes the information, from a number of spin density matrices. The size of the spin polarization that is removed is calculated for particular cases.