Perfect state transfer in XX chains induced by boundary magnetic fields

TL;DR

This paper explains how boundary magnetic fields induce near-perfect quantum state transfer in XX spin chains by localizing boundary states, supported by analytical insights.

Contribution

It provides a simple analytical explanation for boundary-induced perfect state transfer in XX chains, expanding understanding beyond numerical observations.

Findings

Boundary magnetic fields enable near-perfect quantum state transfer.

Localized boundary states are key to the phenomenon.

Analytical model explains the boundary effects clearly.

Abstract

A recent numerical study of short chains found near-perfect quantum state transfer between the boundary sites of a spin-1/2 XX chain if a sufficiently strong magnetic field acts on these sites. We show that the phenomenon is based on a pair of states strongly localized at the boundaries of the system and provide a simple quantitative analytical explanation.