Entanglement and objectivity in pure dephasing models

Abstract

We study the relation between the emergence of objectivity and qubit-environment entanglement generation. We find that although entanglement with the unobserved environments is irrelevant (since sufficiently strong decoherence can occur regardless), entanglement with the observed environments is crucial. In fact, the appearance of an objective qubit-observed-environment state is strictly impossible if their joint evolution does not lead to entanglement. Furthermore, if a single observer has access to a single environment (no macrofractions) then the required orthogonality of the observed environmental states comes only as a consequence of the system-enviornment state becoming strongly entangled (maximally entangled for the given initial occupation of the qubit if the environmental state is initially pure).

9 pages, no figures

References in corpus (22)

• Dynamical decoupling and noise spectroscopy with a superconducting flux qubit
• Optimized Dynamical Decoupling in a Model Quantum Memory
• Quantum Darwinism
• Theory of electron spin decoherence by interacting nuclear spins in a quantum dot
• Spectroscopy of Surface-Induced Noise Using Shallow Spins in Diamond
• Pure quantum dephasing of a solid state electron spin qubit in a large nuclear spin bath coupled by long-range hyperfine-mediated interactions
• The quantum Chernoff bound as a measure of distinguishability between density matrices: application to qubit and Gaussian states
• Quantum many-body theory for electron spin decoherence in nanoscale nuclear spin baths
• Environmental noise spectroscopy with qubits subjected to dynamical decoupling
• Complete disentanglement by partial pure dephasing
• Spectrum of the Nuclear Environment for GaAs Spin Qubits
• Strong Quantum Darwinism and Strong Independence is equivalent to Spectrum Broadcast Structure
• Entanglement is necessary for emergent classicality in all physical theories
• Collisional unfolding of quantum Darwinism
• Objectivity in non-Markovian spin-boson model
• Decoherence of two entangled spin qubits coupled to an interacting sparse nuclear spin bath: application to nitrogen vacancy centers
• Equivalence of qubit-environment entanglement and discord generation via pure dephasing interactions and the consequences thereof
• Criteria for system-environment entanglement generation for systems of any size in pure-dephasing evolutions
• System information propagation for spin structures
• Decoherence of spin registers revisited
• Information transfer during the universal gravitational decoherence
• Redundant information encoding in QED during decoherence

Cited by in corpus (20)

• Roads to objectivity: Quantum Darwinism, Spectrum Broadcast Structures, and Strong quantum Darwinism -- a review
• Quantum Darwinism in a structured spin environment
• Witnessing non-objectivity in the framework of strong quantum Darwinism
• Correlations, information backflow, and objectivity in a class of pure dephasing models
• A measure of qubit environment entanglement for pure dephasing evolutions
• Transfer and teleportation of system-environment entanglement
• A glimpse of objectivity in bipartite systems for non-entangling pure dephasing evolutions
• Amplification, inference, and the manifestation of objective classical information
• Appearance of objectivity for NV centers interacting with dynamically polarized nuclear environment
• Blurred quantum Darwinism across quantum reference frames
• The importance of using the averaged mutual information when quantifying quantum objectivity
• The meaning of redundancy and consensus in quantum objectivity
• System-bath entanglement of noninteracting fermionic impurities: Equilibrium, transient, and steady-state regimes
• Decoherence and information encoding in quantum reference frames
• Qubit-environment entanglement in time-dependent pure dephasing
• Convex-roof entanglement measures of density matrices block diagonal in disjoint subspaces for the study of thermal states
• A signature of quantumness in pure decoherence control
• Thermality versus objectivity: can they peacefully coexist?
• Commutativity and the emergence of classical objectivity
• Decoherence and objectivity in higher spin environments