1995/04/30 by Benni Reznik, B. Reznik
Computer Science · Physics and Astronomy · #Quantum Information and Cryptography #Quantum Mechanics and Applications #Spectroscopy and Quantum Chemical Studies #gr-qc #hep-th #quant-ph
paper · pdf · doi:10.1103/physrevlett.76.1192
published as Phys.Rev.Lett. 76 (1996) 1192-1195 · 13 pages, latex. Revised version. To appear in Phys. Rev. Lett
arxiv created 1995/12/19 · openalex publication_date 1996/02/19 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose an extended quantum mechanical formalism that is based on a wave operator \stackrel^\ensuremath\varrho, which is related to the ordinary density matrix via \ensuremathρ\phantom\rule0ex0ex=\phantom\rule0ex0ex\stackrel^\ensuremath\varrho\stackrel^\ensuremath\varrho^\ifmmode†\else\textdagger\fi. This formalism allows a (generalized) unitary evolution between pure and mixed states. It also preserves much of the connection between symmetries and conservation laws. The new formalism is illustrated for the case of a two-level system.