Properties of donor qubits in ZnO formed by indium ion implantation

TL;DR

This study demonstrates that indium ion implantation in ZnO creates donor qubits with optical and spin properties comparable to in situ doping, offering a promising approach for solid-state quantum information applications.

Contribution

It shows that In ion implantation can reliably produce donor qubits in ZnO with favorable optical and spin characteristics, advancing deterministic qubit fabrication methods.

Findings

In implanted In donors exhibit linewidths less than 10 GHz.

Longitudinal spin relaxation times exceed those of Ga donors.

Hyperfine interaction with In nuclei observed via Raman spectroscopy.

Abstract

Shallow neutral donors (D$^{0}$) in ZnO have emerged as a promising candidate for solid-state spin qubits. Here, we report on the formation of D$^{0}$ in ZnO via implantation of In and subsequent annealing. The implanted In donors exhibit optical and spin properties on par with $\textit{in situ}$ doped donors. The inhomogeneous linewidth of the donor-bound exciton transition is less than 10 GHz, comparable to the optical linewidth of $\textit{in situ}$ In. Longitudinal spin relaxation times ($T_1$) exceed reported values for $\textit{in situ}$ Ga donors, indicating that residual In implantation damage does not degrade $T_1$. Two laser Raman spectroscopy on the donor spin reveals the hyperfine interaction of the donor electron with the spin-9/2 In nuclei. This work is an important step toward the deterministic formation of In donor qubits in ZnO with optical access to a long-lived nuclear spin memory.