Effects of anisotropy on optimal dense coding

TL;DR

This paper investigates how anisotropic interactions in two-qubit models affect the efficiency of optimal dense coding, revealing conditions for successful dense coding and the disconnect between entanglement and dense coding capability.

Contribution

It provides a detailed analysis of the impact of anisotropic XXZ and Dzyaloshinski-Moriya interactions on dense coding, establishing conditions for its viability in these models.

Findings

Certain anisotropic parameters enable dense coding

Entanglement does not always imply dense coding capability

Conditions for valid dense coding depend on model parameters

Abstract

We study optimal dense coding with thermal entangled states of a two-qubit anisotropic \emph{XXZ} model and a Heisenberg model with Dzyaloshinski-Moriya (DM) interactions. The DM interaction is another kind of anisotropic antisymmetric exchange interaction. The effects of these two kinds of anisotropies on dense coding are studied in detail for both the antiferromagnetic and ferromagnetic cases. For the two models, we give the conditions that the parameters of the models have to satisfy for a valid dense coding. We also found that even though there is entanglement, it is unavailable for our optimal dense coding, which is the same as entanglement teleportation.