Quantum Darwinism in a Composite System: Objectivity versus Classicality

We investigate the implications of quantum Darwinism in a composite quantum system with interacting constituents exhibiting a decoherence-free subspace. We consider a two-qubit system coupled to an -qubit environment via a dephasing interaction. For excitation preserving interactions between the sys...

Full description

Saved in:
Bibliographic Details
Published in:Entropy (Basel, Switzerland) Switzerland), 2021-07, Vol.23 (8), p.995
Main Authors: Çakmak, Barış, Müstecaplıoğlu, Özgür E, Paternostro, Mauro, Vacchini, Bassano, Campbell, Steve
Format: Article
Language:English
Subjects:
decoherence
Entropy
Hilbert space
Objectivity
open quantum systems
quantum Darwinism
Quantum theory
Qubits (quantum computing)
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We investigate the implications of quantum Darwinism in a composite quantum system with interacting constituents exhibiting a decoherence-free subspace. We consider a two-qubit system coupled to an -qubit environment via a dephasing interaction. For excitation preserving interactions between the system qubits, an analytical expression for the dynamics is obtained. It demonstrates that part of the system Hilbert space redundantly proliferates its information to the environment, while the remaining subspace is decoupled and preserves clear non-classical signatures. For measurements performed on the system, we establish that a non-zero quantum discord is shared between the composite system and the environment, thus violating the conditions of strong Darwinism. However, due to the asymmetry of quantum discord, the information shared with the environment is completely classical for measurements performed on the environment. Our results imply a dichotomy between objectivity and classicality that emerges when considering composite systems.
ISSN:1099-4300
1099-4300
DOI:10.3390/e23080995