Creating quantum correlations through local non-unitary memoryless channels

TL;DR

This paper demonstrates that local memoryless noise can generate quantum correlations from classical states, with analytical proof and a physical interpretation, challenging the notion that noise only destroys quantum features.

Contribution

It provides the first analytical demonstration that local Markovian noise can create quantum correlations from classical states, supported by a Bloch sphere visualization.

Findings

Quantum discord increases under local amplitude-damping noise

Analytical expression derived for quantum discord in this process

Physical mechanism explained via Bloch sphere representation

Abstract

We show that two qubits, initially in a fully classical state, can develop significant quantum correlations as measured by the quantum discord (QD) under the action of a local memoryless noise (specifically we consider the case of a Markovian amplitude-damping channel). This is analytically proven after deriving in a compact form the QD for the class of separable states involved in such a process. We provide a picture in the Bloch sphere that unambiguously highlights the physical mechanism behind the effect regardless of the specific measure of QCs adopted.