NMR dynamics of quantum discord for spin-carrying gas molecules in a closed nanopore

TL;DR

This paper develops a method to calculate quantum discord in X states and applies it to analyze flickering quantum correlations in spin-carrying gas molecules within a nanopore under strong magnetic fields.

Contribution

It introduces a new transformation and a piecewise formula for quantum discord calculation, enabling analysis of quantum correlations in gas molecules in confined environments.

Findings

Quantum discord exhibits flickering behavior in gas molecules within nanopores.

The method accurately describes quantum correlation dynamics under strong magnetic fields.

Analytical and numerical tools improve understanding of quantum information in physical systems.

Abstract

A local orthogonal transformation that transforms any centrosymmetric (CS) matrix of fourth order to the X form is found. A picewise-analytic-numerical formula Q=min{Q_\pi/2,Q_\theta,Q_0}, where Q_\pi/2 and Q_0 are analytical expressions and the branch Q_{\theta} is found by numerical searching the optimal measurement angle \theta\in(0,\pi/2), is proposed to calculate the quantum discord Q of general X state. The developed approaches are applied to a quantitative description of recently predicted flickerings (periodic birth and death) of the quantum-information pair correlation between nuclear 1/2 spin of atoms or molecules of a gas (for examples Xe^129) in a finite asymmetric volume in the presence of a strong magnetic field.