Quantum information processing using frozen core Y³⁺ spins in Eu³⁺:Y₂SiO₅

In this paper, we present a method to investigate and control the dynamics of the nearby host nuclear spins (the 'frozen core') about a rare-earth ion doped in a crystal. Optically detected, double quantum magnetic resonance measurements were conducted on Eu³⁺ Y₂SiO₅. The distinct magnetic resonant frequencies of nearby Y³⁺ spins were measured along with the lifetime and coherence time of an individual Y³⁺ spin. We demonstrate an entangling gate between the Eu³⁺ spins and a Y³⁺ spin associated with a particular position. Further, we propose a method to initialize the Y³⁺ spin states, enabling the Y³⁺ spins to be used as a quantum resource for quantum information applications.