2003/08/28 by W. H. Zurek, Zurek, W. H.
Arts and Humanities · Physics and Astronomy · #FOS: Physical sciences #Philosophy and History of Science #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/0308163
arxiv created 2003/08/28 · openalex publication_date 2003/08/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Effective classicality of a property of a quantum system can be defined using redundancy of its record in the environment. This allows quantum physics to approximate the situation encountered in the classical world: The information about a classical system can exist independently from its state. In quantum theory this is no longer possible: In an isolated quantum system the state and the information about it are inextricably linked, and any measurement may -- and usually will -- reset that state. However, when the information about the state of a quantum system is spread throughout the environment, it can be treated (almost) as in classical physics.