Disorder-safe entanglement transfer through ladder qubit chains

TL;DR

This paper proposes a disorder-resistant entanglement transfer protocol in a ladder spin chain, where high-fidelity transfer is achieved through a protected subspace that improves with increasing disorder.

Contribution

It introduces a novel scheme for robust entanglement transfer in disordered ladder qubit chains using a protected subspace that enhances fidelity as disorder increases.

Findings

High-fidelity entanglement transfer via a disorder-protected subspace.

Leakage from the subspace decreases with increasing disorder.

Transfer fidelity improves with increasing disorder strength.

Abstract

We study an entanglement transfer protocol in a two-leg ladder spin-1/2 chain in the presence of disorder. In the regime where on-site energies and the intrachain couplings follow aproximately constant proportions locally, we set up a scheme for high-fidelity state transfer via a disorder-protected subspace wherein fluctuations in the parameters do not depend on the global disorder of the system, accounted by $W$. Moreover, we find that the leakage of information from that subspace is actually suppressed upon increasing $W$ and thus the transfer fidelity, evaluated through the entanglement concurrence at the other end of the chain, builds up with the disorder strength.