Entanglement structures in disordered chains of nitrogen-vacancy centers

TL;DR

This paper explores the entanglement structures in chains of nitrogen-vacancy centers in diamond, showing that most eigenstates exhibit strong connectivity, which is resilient to positional disorder, relevant for quantum register applications.

Contribution

It provides a detailed analysis of eigenstate connectivity in NV center chains, highlighting robustness against disorder and implications for quantum information processing.

Findings

Most eigenstates show strong connectivity, especially in the spectrum center.

Positional disorder can alter but rarely suppress connectivity.

Connectivity remains substantial even in disordered chains.

Abstract

A recent study [Phys. Rev. B 17 174111 (2022)] has hypothesized the assembly, along a specific type of one-dimensional defects of diamond, of chains of nitrogen-vacancy (NV) centers, potentially enabling the creation of qubit registers via their dipole-coupled electron spins. Here we investigate the connectivity of chains of up to ten coupled spins, mediated by the bi- and multipartite entanglement of their eigenstates. Rather conveniently, for regularly spaced spins the vast majority of the eigenstates displays strong connectivity, especially towards the center of the spectrum and for longer chains. Furthermore, positional disorder can change, and possibly reduce, the connectivity of the register, but seldom suppresses it.