Angular dependent micro-ESR characterization of a locally doped Gd3+:Al2O3 system

TL;DR

This study demonstrates the successful angular-dependent micro-ESR characterization of a locally implanted Gd$^{3+}$:Al$_2$O$_3$ system coupled with a superconducting resonator, confirming lattice integration and highlighting the importance of controlled implantation.

Contribution

It provides detailed micro-ESR analysis of a locally doped Gd$^{3+}$:Al$_2$O$_3$ system coupled to a superconducting resonator, showing lattice site preservation despite surface implantation.

Findings

Micro-ESR spectra match the theoretical Hamiltonian.

Implantation maintains crystalline symmetry.

Distinct contributions from resonator microwave components.

Abstract

Interfacing rare-earth doped crystals with superconducting circuit architectures provides an attractive platform for quantum memory and transducer devices. Here we present the detailed characterization of such a hybrid system: a locally implanted rare-earth Gd$^{3+}$ in Al$_2$O$_3$ spin system coupled to a superconducting micro-resonator. We investigate the properties of the implanted spin system through angular dependent micro-resonator electron spin resonance (micro-ESR) spectroscopy. We find, despite the high energy near-surface implantation, the resulting micro-ESR spectra to be in excellent agreement with the modelled Hamiltonian, supporting the integration of dopant ions into their relevant lattice sites whilst maintaining crystalline symmetries. Furthermore, we observe clear contributions from individual microwave field components of our micro-resonator, emphasising the need for controllable local implantation.