Quantum communication through a single-spin channel in the presence of an environment

Abstract

A quantum state represented by a qubit is to be transmitted to a distant spin through a one-channel spin chain obeying the isotropic XY Model with a transverse magnetic field. We study the effects of letting the channel be a qutrit instead of a qubit, and letting the channel be subjected to an intermediate environment, as per Lindblad dynamics. Nontrivial findings include increase in fidelity when a qutrit serves as the channel, and the interaction of the channel with the environment stabilizes communication at a time dictated by the strength of interaction.