Extracting Information from Qubit-Environment Correlations

Author(s)

Reina, John H. ^{[1, 2]} ; Susa, Cristian E. ^{[1, 2]} ; Fanchini, Felipe F. ^[3]

Affiliation

^[1] Univ Valle, Dept Fis, Cali 25360 - Colombia

^[2] Ctr Bioinformat & Photon CIBioFI, Cali - Colombia

^[3] UNESP, Fac Ciencias, Dept Fis, BR-17033360 Bauru, SP - Brazil

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 4, DEC 17 2014.
• Web of Science Citations: 11

Abstract

Most works on open quantum systems generally focus on the reduced physical system by tracing out the environment degrees of freedom. Here we show that the qubit distributions with the environment are essential for a thorough analysis, and demonstrate that the way that quantum correlations are distributed in a quantum register is constrained by the way in which each subsystem gets correlated with the environment. For a two-qubit system coupled to a common dissipative environment epsilon, we show how to optimise interqubit correlations and entanglement via a quantification of the qubit-environment information flow, in a process that, perhaps surprisingly, does not rely on the knowledge of the state of the environment. To illustrate our findings, we consider an optically-driven bipartite interacting qubit AB system under the action of epsilon. By tailoring the light-matter interaction, a relationship between the qubits early stage disentanglement and the qubit-environment entanglement distribution is found. We also show that, under suitable initial conditions, the qubits energy asymmetry allows the identification of physical scenarios whereby qubit-qubit entanglement minima coincide with the extrema of the A epsilon and B epsilon entanglement oscillations. (AU)

• FAPESP's process: 08/57856-6 - National Institute of Science and Technology - Quantum Information
• Grantee: Amir Ordacgi Caldeira
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 12/50464-0 - A study of quantum correlations in open quantum systems
• Grantee: Felipe Fernandes Fanchini
• Support Opportunities: Regular Research Grants