Measurement theory for closed quantum systems
arXiv:1404.6963
Abstract
We introduce the concept of a "classical observable" as an operator with vanishingly small quantum fluctuations on a set of density matrices. It is shown how to construct them for a time evolved pure state. The study of classical observables provides a natural starting point to analyse the quantum measurement problem. In particular, it allows to identify Schrödinger cats and the associated projection operators intrinsically, without the need to invoke an environment. We discuss how our new approach relates to the open system analysis of the quantum measurement problem.
arXiv comment4 pages, 3 figures, supplemental information
References in corpus (8)
- Decoherence, einselection, and the quantum origins of the classical
- Thermalization and its mechanism for generic isolated quantum systems
- Nonequilibrium dynamics of closed interacting quantum systems
- Classical Equations for Quantum Systems
- Reconstruction of non-classical cavity field states with snapshots of their decoherence
- Equilibration of quantum systems and subsystems
- Microscopic diagonal entropy and its connection to basic thermodynamic relations
- Quantum Darwinism in an Everyday Environment: Huge Redundancy in Scattered Photons