Remote control of quantum correlations in a two-qubit receiver by a three-qubit sender

Abstract

We study remote control of quantum correlations (discord) in a subsystem of two qubits (receiver) via parameters of the initial state of another three-qubit subsystem (sender) connected to the receiver by an inhomogeneous spin s = 1/2 chain. We propose two parameters characterizing the creatable correlations. The first parameter is the discord between the receiver and the remainder of the spin s = 1/2 chain, and it concerns the mutual correlations between these two subsystems. The second parameter is the discord between the two nodes of the receiver and describes the inner correlations of the receiver. We study the dependence of these two discords on the inhomogeneity parameter of the spin chain.