Conditions on local operations to create quantum correlation

TL;DR

This paper characterizes the conditions under which local quantum operations can generate quantum correlations from classical states, highlighting the role of mixedness especially in higher-dimensional systems.

Contribution

It provides necessary and sufficient conditions for local channels to create quantum correlation, extending understanding from qubits to higher-dimensional systems.

Findings

Channels that cannot create quantum correlation are either completely decohering or mixing for two-qubit states.

In higher dimensions, mixing channels can generate quantum correlation from classical states.

Mixedness plays a crucial role in the creation of quantum correlation in high-dimensional quantum systems.

Abstract

We prove the condition for local trace-preserving channels to create quantum correlation from initially classical states. For two-qubit states, the necessary and sufficient condition for a channel that cannot create quantum correlation in any initially classical state is that it is either a completely decohering channel or a mixing channel. For states in higher dimensions, we show that even a mixing channel can create quantum correlation from a classically correlated state. Our results reveal that mixedness is important for creation of quantum correlation in high-dimension quantum systems.