Fast and robust magnon transport in a spin chain

TL;DR

This paper introduces a fast, high-fidelity magnon transport protocol in a spin chain by mapping it to a harmonic oscillator control problem, outperforming adiabatic methods and revealing a speed limit for the process.

Contribution

It develops a novel control scheme for magnon transport in spin chains based on an analytic mapping, enabling faster and more robust transfer than existing adiabatic protocols.

Findings

The protocol achieves significantly faster magnon transport.

It demonstrates high fidelity and robustness in the transfer process.

A heuristic speed limit for the transport protocol is identified.

Abstract

A protocol for fast and robust magnon transport in a one-dimensional spin chain is devised. Employing an approximate mapping between the chain and a single harmonically trapped particle, we exploit the known analytic control protocols for the latter and adopt them to achieve fast, high-fidelity transport in the chain. We compare the performance with finite time adiabatic protocols, establishing that the designed scheme allows for significantly faster and more stable transport. Furthermore, we show that a sharp transition exists between regions in which the protocol is effective and when it breaks down, giving rise to a heuristic speed limit for the process.