Exhaustive characterization of modified Si vacancies in 4H-SiC

Abstract

The negatively charged silicon vacancy (${\mathrm{V}}_{\mathrm{Si}}^{-}$) in silicon carbide is a well-studied point defect for quantum applications. At the same time, a closer inspection of ensemble photoluminescence and electron paramagnetic resonance measurements reveals an abundance of related but so far unidentified signals. In this study, we search for defects in 4H-SiC that explain the above magneto-optical signals in a defect database generated by Automatic Defect Analysis and Qualification (ADAQ) workflows. This search reveals only one class of atomic structures that exhibit silicon-vacancy-like properties in the data: a carbon antisite (${\mathrm{C}}_{\mathrm{Si}}$) within sub-nanometer distances from the silicon vacancy only slightly alters the latter without affecting the charge or spin state. Such a perturbation is energetically bound. We consider the formation of ${\mathrm{V}}_{\mathrm{Si}}^{-}+{\mathrm{C}}_{\mathrm{Si}}$ up to 2 nm distance and report their zero phonon lines and zero field splitting values. In addition, we perform high-resolution photoluminescence experiments in the silicon vacancy region and find an abundance of lines. Comparing our computational and experimental results, several configurations show great agreement. Our work demonstrates the effectiveness of a database with high-throughput results in the search for defects in quantum applications.

References in corpus (5)

• Engineering near infrared single photon emitters in ultrapure silicon carbide
• Resonant addressing and manipulation of silicon vacancy qubits in silicon carbide
• Universal coherence protection in a solid-state spin qubit
• Identification of Si-vacancy related room temperature qubits in 4H silicon carbide
• Strain modulation of Si vacancy emission from SiC micro- and nanoparticles

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• Na in Diamond: High Spin Defects Revealed by the ADAQ High-Throughput Computational Database
• First-principles computational methods for quantum defects in two-dimensional materials: A perspective
• Scalable registration of single quantum emitters within solid immersion lenses through femtosecond laser writing
• NV-like Defects More Common Than Four-Leaf Clovers: A Perspective on High-Throughput Point Defect Data
• Coupling 4H-Silicon Carbide spins to a microwave resonator at milli-Kelvin temperature