Quantum state transfer with sufficient fidelity

TL;DR

This paper introduces an inhomogeneous XX spin chain model that enables high-fidelity quantum state transfer with bounded coupling strengths, bridging the gap between perfect transfer models and practical implementations.

Contribution

It proposes a new inhomogeneous XX spin chain model that balances high fidelity transfer with manageable coupling strengths, improving upon previous perfect transfer models.

Findings

Achieves high-fidelity quantum state transfer

Coupling strengths remain bounded as system size increases

Interpolates between Krawtchouk and homogeneous XX chains

Abstract

We consider an inhomogeneous XX spin chain which interpolates between the Krawtchouk one with perfect state transfer and the homogeneous XX chain. This model can be exploited in order to perform state transfer of a qubit with sufficiently good fidelity. The advantage of this model with respect to the Krawtchouk chain is that while it achieves efficient state transfer, the coupling strengths are capped and do not become excessively large as the number of sites grows.