Quantum Correlation Dynamics in Controlled Two-Coupled-Qubit Systems

TL;DR

This paper analyzes how quantum correlations like entanglement and discord evolve over time in a driven two-qubit system, revealing the physical mechanisms behind their appearance and disappearance.

Contribution

It provides an exact analytical study of quantum correlation dynamics in a controlled two-qubit system starting from a Werner state, highlighting the invariance of the X structure.

Findings

Entanglement shows appearance and disappearance over time.

Quantum discord persists and evolves asymptotically.

The physical origin of correlation dynamics is linked to state invariance.

Abstract

We study and compare the time evolutions of concurrence and quantum discord in a driven system of two interacting qubits prepared in a generic Werner state. The~corresponding quantum dynamics is exactly treated and manifests the appearance and disappearance of entanglement. Our analytical treatment transparently unveils the physical reasons for the occurrence of such a phenomenon, relating it to the dynamical invariance of the $X$ structure of the initial state. The~quantum correlations which asymptotically emerge in the system are investigated in detail in terms of the time evolution of the fidelity of the initial Werner state.