High-yield engineering and identification of oxygen-related modified divacancies in 4H-SiC

TL;DR

This study presents a high-yield method for engineering and identifying oxygen-related divacancies in 4H-SiC, revealing their atomic structure and superior quantum properties for scalable quantum technology applications.

Contribution

The paper introduces a controllable oxygen-ion implantation technique to efficiently produce and identify oxygen-related divacancies in 4H-SiC, clarifying their structure and enhancing their quantum properties.

Findings

Over 90% of defects are single oxygen-vacancy centers with superior optical and spin coherence.

Four types of oxygen-related divacancies are experimentally resolved and identified.

High-density ensembles with distinct temperature-dependent spin properties are achieved.

Abstract

Modified divacancies in the 4H polytype of silicon carbide (SiC) exhibit enhanced charge stability and spin addressability at room temperature, making them attractive for quantum applications. However, their low formation yield and lack of direct structural identification have hindered progress. Here, we demonstrate a controllable method for high-yield engineering and identification of oxygen-related modified divacancy color centers in 4H-SiC via oxygen-ion implantation. Based on their distinct optical and spin-resonance characteristics, we experimentally resolve four types of modified divacancies. Furthermore, by measuring isotope-resolved 17O hyperfine interactions, we identify them as the four crystallographic configurations of oxygen-vacancy (OV) complexes. Remarkably, single OV centers account for over 90% of the total defect population and exhibit superior optical properties and spin coherence compared with defects created by conventional carbon or nitrogen implantation. We characterize the zero-phonon lines of these OV centers and reveal distinct temperature-dependent behavior in spin-readout contrast. By optimizing implantation dose and annealing temperature, we achieve high-density ensembles and observe Rabi-oscillation beating patterns associated with different orientations of basal-type defects. These results establish a high-yield route for scalable engineering of these four oxygen-related modified divacancies in 4H-SiC and clarify their atomic structure, opening new opportunities for solid-state quantum technologies.