Sudden Change of Quantum Discord under Single Qubit Noise

TL;DR

This paper demonstrates that quantum discord can undergo sudden changes even when only one qubit in an entangled pair is subjected to noise, highlighting the non-necessity of full-system noise for such transitions.

Contribution

It reveals that single-qubit noise alone can induce sudden changes in quantum discord, expanding understanding of quantum correlation dynamics under localized noise.

Findings

Quantum discord exhibits sudden change under single-qubit noise.

Composite noise on entire system is not required for quantum correlation transitions.

Different noisy environments can cause these sudden changes independently.

Abstract

We show that the sudden change of quantum correlation can occur even when only one part of the composite entangled state is exposed to a noisy environment. Our results are illustrated through the action of different noisy environments individually on a single qubit of quantum system. Composite noise on the whole of the quantum system is thus not the necessarily condition for the occurrence of sudden transition for quantum correlation.