Emergence of Objectivity for Quantum Many-Body Systems

Abstract

We examine the emergence of objectivity for quantum many-body systems in a setting without an environment to decohere the system's state, but where observers can only access small fragments of the whole system. We extend the result of Reidel (2017) to the case where the system is in a mixed state, measurements are performed through POVMs, and imprints of the outcomes are imperfect. We introduce a new condition on states and measurements to recover full classicality for any number of observers. We further show that evolutions of quantum many-body systems can be expected to yield states that satisfy this condition whenever the corresponding measurement outcomes are redundant.

References in corpus (20)

• Quantum Steering
• Quantum Darwinism
• Joint measurability of generalized measurements implies classicality
• Objective properties from subjective quantum states: Environment as a witness
• Quantum Darwinism: Entanglement, branches, and the emergent classicality of redundantly stored quantum information
• Generic emergence of classical features in quantum Darwinism
• Environment as a Witness: Selective Proliferation of Information and Emergence of Objectivity in a Quantum Universe
• A simple example of "Quantum Darwinism": Redundant information storage in many-spin environments
• Quantum Darwinism in an Everyday Environment: Huge Redundancy in Scattered Photons
• Quantum Darwinism in quantum Brownian motion: the vacuum as a witness
• Objectivity in the Photonic Environment Through State Information Broadcasting
• Non-disturbing quantum measurements
• Quantum Darwinism, Classical Reality, and the Randomness of Quantum Jumps
• The Objective Past of a Quantum Universe: Redundant Records of Consistent Histories
• Quantum Theory of the Classical: Quantum Jumps, Born's Rule, and Objective Classical Reality via Quantum Darwinism
• Amplification, Redundancy, and the Quantum Chernoff Information
• Amplification, Decoherence, and the Acquisition of Information by Spin Environments
• Classical branch structure from spatial redundancy in a many-body wavefunction
• Quantum theory realises all joint measurability graphs
• Emergent classicality in general multipartite states and channels

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• Toy Model Challenging Prevailing Definitions of Classicality