Environment-induced sudden transition in quantum discord dynamics

TL;DR

This paper demonstrates environment-induced sudden transitions and noise immunity in quantum discord dynamics using room temperature nuclear magnetic resonance, highlighting the robustness of quantum correlations in decohering environments.

Contribution

It experimentally shows the sudden-change phenomenon and noise resilience of quantum discord in a realistic decohering environment.

Findings

Observation of sudden-change in quantum discord dynamics

Quantum discord exhibits immunity against certain noise sources

Experimental validation in a room temperature NMR setup

Abstract

Non-classical correlations play a crucial role in the development of quantum information science. The recent discovery that non-classical correlations can be present even in separable (unentangled) states has broadened this scenario. This generalized quantum correlation has been increasing relevance in several fields, among them quantum communication, quantum computation, quantum phase transitions, and biological systems. We demonstrate here the occurrence of the sudden-change phenomenon and immunity against some sources of noise for the quantum discord and its classical counterpart, in a room temperature nuclear magnetic resonance setup. The experiment is performed in a decohering environment causing loss of phase relations among the energy eigenstates and exchange of energy between system and environment, resulting in relaxation to a Gibbs ensemble.