26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Donor atoms in enriched silicon: Electrically detected magnetic resonance studies of clock transitions on sparse spin ensembles

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Poster AIP | Quantum Science and Technology (QST)

Description

Using electrically detected magnetic resonance (EDMR) spectroscopy we have investigated donor spin ensembles in isotopically enriched silicon, using both conventional chemical vapour deposition methods and an ion beam enrichment method compatible with conventional ion implanters [1,2]. The EDMR technique reveals details about the existence and local environment of donors in semiconductor hosts, information relevant for characterizing and optimising host materials for donor-qubit architectures. The use of electrical detection, by way of a resonant conductivity modulation, grants a sensitivity that can in principle be scaled down to a small ensemble of donors (c.a. 100) [3]. Devices for EDMR spectroscopy offer an intermediate measurement and fabrication complexity between traditional bulk techniques and state-of-the-art single-donor architectures. It therefore holds the promise of enabling rapid iteration during the development of implantation and isotopic enrichment protocols, ensuring that the sophisticated and demanding qubit fabrication process is brought to bear on already-optimized materials.

Here we summarize our progress to date in using EDMR to study Sb, P and As donors in silicon. By directly comparing devices built upon natural and isotopically enriched silicon, we show that the degree of isotopic enrichment is indeed reflected in EDMR spectral linewidths. Moreover, we directly demonstrate that at clock-transitions (special regions in phase space where donor resonances become insensitive to magnetic field noise) the spectral linewidth becomes independent of isotopic enrichment.

[1] Highly 28-Si Enriched Silicon by Localised Focused Ion Beam Implantation, R Acharya et al, doi.org/10.1038/s43246-024-00498-0
[2] Silicon spin vacuum: Isotopically enriched silicon-on-insulator and silicon from ultrahigh fluence ion implantation, S. Q. Lim et al doi.org/10.1103/787r-9jps
[3] Electrically detected magnetic resonance in ion-implanted Si:P nanostructures, D. R. McCamey et al, doi.org/10.1063/1.2358928
[4] Mapping the magnetic clock transition of near-surface 75 As donor spins in silicon using electrically detected magnetic resonance, R. Acharya et al doi.org/10.48550/arXiv.2604.24090