Effects of impurity on fidelity of quantum state transfer via spin channels

TL;DR

This paper studies how spin and magnetic impurities affect the fidelity of quantum state transfer in spin chains, revealing that magnetic impurities can hinder perfect transfer despite spin impurities not doing so.

Contribution

It introduces an analysis of impurity effects on quantum state transfer fidelity, highlighting the differing impacts of spin versus magnetic impurities.

Findings

Spin impurities do not prevent perfect state transfer.

Magnetic impurities can destroy perfect transfer.

Both impurities together may impair transfer fidelity.

Abstract

By adopting the concept of fidelity, we investigated efficiency of quantum state transfer with the XX chain as the quantum channel. Different from the previous works, we concentrated on effects of spin and magnetic impurity on fidelity of quantum state transfer. Our results revealed that the spin impurity cannot prevent one from implementing perfect transfer of an arbitrary one-qubit pure state across the spin channel, however, the presence of magnetic impurity or both spin and magnetic impurities may destroy the otherwise perfect spin channels.