Compatibility of Quantum Measurements and the Emergence of Classical Objectivity
arXiv:2411.10862 · doi:10.1103/PhysRevA.111.042217
Abstract
The study of measurements in quantum mechanics exposes many of the ways in which the quantum world is different. For example, one of the hallmarks of quantum mechanics is that observables may be incompatible, implying among other things that it is not always possible to find joint probability distributions which fully capture the joint statistics of multiple measurements. Instead, one must employ more general tools such as the Kirkwood-Dirac quasiprobability (KDQ) distribution, which may exhibit negative or non-real values heralding non-classicality. In this Letter, we consider the KDQ distributions describing arbitrary collections of measurements on disjoint components of some generic multipartite system. We show that the system dynamics ensures that these distributions are classical if and only if the Hamiltonian supports Quantum Darwinism. Thus, we demonstrate a fundamental relationship between these two notions of classicality and their emergence in the quantum world.
arXiv comment6 pages, 1 figure
References in corpus (33)
- Decoherence, einselection, and the quantum origins of the classical
- Quantum Darwinism
- Measuring the characteristic function of the work distribution
- Objective properties from subjective quantum states: Environment as a witness
- Quantum Darwinism: Entanglement, branches, and the emergent classicality of redundantly stored quantum information
- Jarzynski-like equality for the out-of-time-ordered correlator
- Generic emergence of classical features in quantum Darwinism
- Environment as a Witness: Selective Proliferation of Information and Emergence of Objectivity in a Quantum Universe
- Quantum theory of successive projective measurements
- Quantum origins of objectivity
- Out-of-Time-Ordered-Correlator Quasiprobabilities Robustly Witness Scrambling
- A simple example of "Quantum Darwinism": Redundant information storage in many-spin environments
- Quantum Darwinism in an Everyday Environment: Huge Redundancy in Scattered Photons
- The Rise and Fall of Redundancy in Decoherence and Quantum Darwinism
- Kirkwood-Dirac quasiprobability approach to the statistics of incompatible observables
- Quantum circuits for measuring weak values, Kirkwood--Dirac quasiprobability distributions, and state spectra
- Strong Quantum Darwinism and Strong Independence is equivalent to Spectrum Broadcast Structure
- Redundant Information from Thermal Illumination: Quantum Darwinism in Scattered Photons
- Quantum Theory of the Classical: Einselection, Envariance, Quantum Darwinism and Extantons
- Roads to objectivity: Quantum Darwinism, Spectrum Broadcast Structures, and Strong quantum Darwinism -- a review
- Eavesdropping on the Decohering Environment: Quantum Darwinism, Amplification, and the Origin of Objective Classical Reality
- Properties and Applications of the Kirkwood-Dirac Distribution
- Quasiprobabilities in quantum thermodynamics and many-body systems
- The role of information back-flow in the emergence of quantum Darwinism
- Generic emergence of objectivity of observables in infinite dimensions
- Projective measurements can probe non-classical work extraction and time-correlations
- Generic appearance of objective results in quantum measurements
- Redundantly amplified information suppresses quantum correlations in many-body systems
- Kirkwood-Dirac representations beyond quantum states (and their relation to noncontextuality)
- Pointer states and quantum Darwinism with 2-body interactions
- Branching States as The Emergent Structure of a Quantum Universe
- Classifying two-body Hamiltonians for Quantum Darwinism
- Refined diamond norm bounds on the emergence of objectivity of observables