Metrological approach to the emergence of classical objectivity

Abstract

We present a precise characterization of the onset of classicality that combines the formalism of quantum Darwinism with the tools from quantum metrology. We show that the quantum Fisher information provides a useful metric for assessing the rate at which classical objectivity emerges. Furthermore, our formalism allows us to explore how the choice of measurement impacts the precision with which an observer can determine the state of the system. For a paradigmatic example of the spin-star model, we demonstrate that optimal measurements lead to the emergence of classicality at an exponential rate. Although other measurements necessarily lead to slower emergence, we importantly show that suboptimal measurements can still saturate the Cramér-Rao bound. By recasting emergent classicality as an information acquisition protocol, our framework provides a precise operational description of quantum Darwinism.

9 pages, 6 figures

References in corpus (41)

• Advances in Quantum Metrology
• Quantum metrology with nonclassical states of atomic ensembles
• Quantum Fisher information matrix and multiparameter estimation
• Quantum Darwinism
• Objective properties from subjective quantum states: Environment as a witness
• Detecting large quantum Fisher information with finite measurement precision
• Environment as a Witness: Selective Proliferation of Information and Emergence of Objectivity in a Quantum Universe
• Quantum origins of objectivity
• Simple expression for the quantum Fisher information matrix
• System-environment correlations and Markovian embedding of quantum non-Markovian dynamics
• Objectivity in the Photonic Environment Through State Information Broadcasting
• The Rise and Fall of Redundancy in Decoherence and Quantum Darwinism
• Revealing the emergence of classicality in nitrogen-vacancy centers
• Precision Limits in Quantum Metrology with Open Quantum Systems
• Strong Quantum Darwinism and Strong Independence is equivalent to Spectrum Broadcast Structure
• Experimental signature of Quantum Darwinism in photonic cluster states
• 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
• Broadcasting Quantum Fisher Information
• Collisional unfolding of quantum Darwinism
• The role of information back-flow in the emergence of quantum Darwinism
• Monitoring of the process of system information broadcasting in time
• Optimal witnessing of the quantum Fisher information with few measurements
• Decoherence without entanglement and Quantum Darwinism
• Robust estimation of the Quantum Fisher Information on a quantum processor
• Redundantly amplified information suppresses quantum correlations in many-body systems
• Reconstruction of classical skyrmions from Anderson towers: quantum Darwinism in action
• Branching States as The Emergent Structure of a Quantum Universe
• Pointer states and quantum Darwinism with 2-body interactions
• Classifying two-body Hamiltonians for Quantum Darwinism
• Metrological symmetries in singular quantum multi-parameter estimation
• A Solvable Model of Quantum Darwinism-Encoding Transitions
• High-dimensional monitoring and the emergence of realism via multiple observers
• The meaning of redundancy and consensus in quantum objectivity
• Emergence of Objectivity for Quantum Many-Body Systems
• The importance of using the averaged mutual information when quantifying quantum objectivity
• Observation of Quantum Darwinism and the Origin of Classicality with Superconducting Circuits
• Compatibility of Quantum Measurements and the Emergence of Classical Objectivity
• Complementarity between decoherence and information retrieval from the environment
• System-environment quantum information flow