Quantum origin of quantum jumps: Breaking of unitary symmetry induced by information transfer and the transition from quantum to classical

Abstract

Measurements transfer information about a system to the apparatus, and then further on -- to observers and (often inadvertently) to the environment. I show that even imperfect copying essential in such situations restricts possible unperturbed outcomes to an orthogonal subset of all possible states of the system, thus breaking the unitary symmetry of its Hilbert space implied by the quantum superposition principle. Preferred outcome states emerge as a result. They provide framework for the ``wavepacket collapse'', designating terminal points of quantum jumps, and defining the measured observable by specifying its eigenstates. In quantum Darwinism, they are the progenitors of multiple copies spread throughout the environment -- the fittest quantum states that not only survive decoherence, but subvert it into carrying information about them -- into becoming a witness.

For comments see Seth Lloyd, NATURE 450, 1167 (2007)

References in corpus (1)

• Relative States and the Environment: Einselection, Envariance, Quantum Darwinism, and the Existential Interpretation

Cited by in corpus (16)

• Quantum Darwinism
• Measurement of Quantum Fluctuations in Geometry
• Relative States and the Environment: Einselection, Envariance, Quantum Darwinism, and the Existential Interpretation
• Quantum Theory of the Classical: Einselection, Envariance, Quantum Darwinism and Extantons
• Eavesdropping on the Decohering Environment: Quantum Darwinism, Amplification, and the Origin of Objective Classical Reality
• Entanglement Symmetry, Amplitudes, and Probabilities: Inverting Born's Rule
• Redundantly amplified information suppresses quantum correlations in many-body systems
• Emergence of the Classical from within the Quantum Universe
• Neutrino oscillations with disentanglement of a neutrino from its partners
• Status of the wave function of Quantum Mechanics, or, What is Quantum Mechanics trying to tell us?
• Consistent histories of systems and measurements in spacetime
• Quantitative bounds to propagation of quantum correlations in many-body systems
• A microscopic derivation of the quantum measurement postulates
• Information transfer in generalized probabilistic theories based on weak repeatability
• Growth of Knowledge and Entropy in Quantum Physics
• Environment-Assisted Shortcuts to Adiabaticity