Universal quantum computing using electro-nuclear wavefunctions of rare-earth ions

TL;DR

This paper proposes a universal quantum computing scheme using the electro-nuclear wavefunctions of rare-earth ions, enabling fast and efficient quantum gate operations through optical activation and dipole interactions.

Contribution

It introduces a novel approach utilizing Kramers rare-earth ions' nuclear spins as passive qubits, with optical activation for fast quantum gate implementation, improving upon existing methods.

Findings

Proposes a scheme for universal quantum computing with rare-earth ions.

Demonstrates faster CNOT gate times compared to previous rare-earth implementations.

Highlights advantages over phosphorus donor atom-based quantum computing in silicon.

Abstract

We propose a scheme for universal quantum computing based on Kramers rare-earth ions. Their nuclear spins in the presence of a Zeeman-split electronic crystal field ground state act as 'passive' qubits which store quantum information. The qubits can be activated optically by fast coherent transitions to excited crystal field states with a magnetic moment. The dipole interaction between these states is used to implement CNOT gates. We compare our proposal with a similar one based on phosphorus donor atoms in silicon and discuss the significantly improved CNOT gate time as compared to rare-earth implementations via the slower dipole blockade.