Decoherence without entanglement and Quantum Darwinism

Abstract

It is commonly believed that decoherence arises as a result of the entangling interaction between a quantum system and its environment, as a consequence of which the environment effectively measures the system, thus washing away its quantum properties. Moreover, this interaction results in the emergence of a classical objective reality, as described by Quantum Darwinism. In this Letter, we show that the widely believed idea that entanglement is needed for decoherence is imprecise. We propose a new mechanism, dynamical mixing, capable of inducing decoherence dynamics on a system without creating any entanglement with its quantum environment. We illustrate this mechanism with a simple and exactly solvable collision model. Interestingly, we find that Quantum Darwinism does not occur if the system undergoes entanglement-free decoherence and, only when the effect of a super-environment introducing system-environment entanglement is taken into account, the emergence of an objective reality takes place. Our results lead to the unexpected conclusion that system-environment entanglement is not necessary for decoherence or information back-flow, but plays a crucial role in the emergence of an objective reality.

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Cited by in corpus (27)

• Quantum collision models: open system dynamics from repeated interactions
• Collision models can efficiently simulate any multipartite Markovian quantum dynamics
• Non-equilibrium steady-states of memoryless quantum collision models
• Eavesdropping on the Decohering Environment: Quantum Darwinism, Amplification, and the Origin of Objective Classical Reality
• Quantum Darwinism in a structured spin environment
• Pairwise tomography networks for many-body quantum systems
• Quantum Darwinism in a composite system: Objectivity versus classicality
• Noise assisted quantum coherence protection in hierarchical environment
• Stochastic collision model approach to transport phenomena in quantum networks
• Correlations, information backflow, and objectivity in a class of pure dephasing models
• Strategies to simulate dephasing-assisted quantum transport on digital quantum computers
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• Classifying two-body Hamiltonians for Quantum Darwinism
• 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
• Observation of Quantum Darwinism and the Origin of Classicality with Superconducting Circuits
• System-bath entanglement of noninteracting fermionic impurities: Equilibrium, transient, and steady-state regimes
• Stochastic versus periodic quantum collision models
• Unifying Collisional Models and the Monte Carlo Metropolis Method: Algorithms for Dynamics of Open Quantum Systems
• Witnessing Objectivity on a Quantum Computer
• Many-body localization and the emergence of quantum darwinism
• Metrological approach to the emergence of classical objectivity
• Commutativity and the emergence of classical objectivity
• Thermality versus objectivity: can they peacefully coexist?