Donor-Acceptor Pairs Near Silicon Carbide Surfaces

Area of Science:

• Quantum Technologies
• Materials Science
• Semiconductor Physics

Background:

• Donor-acceptor pairs (DAPs) in wide-bandgap semiconductors enable optically controllable, long-range dipolar interactions for quantum applications.
• Al-N DAPs in silicon carbide (SiC) are predicted to achieve coherent coupling over 10 nm, but their surface behavior is crucial for implementation.

Purpose of the Study:

• Investigate the influence of surfaces on the stability and optical properties of Al-N DAPs in SiC.
• Introduce and analyze surface-defect pairs (SDPs) for enhanced quantum coupling and hybrid interfaces.

Main Methods:

• First-principles calculations to study Al-N DAPs and vanadium-based SDPs in SiC near surfaces.
• Analysis of electron-phonon coupling, dipole alignment, and optical properties (stimulated emission, photoionization cross sections).

Main Results:

• Al-N DAPs in SiC maintain favorable optical properties near surfaces, with minor increases in electron-phonon coupling.
• Vanadium-based SDPs on OH-terminated 4H-SiC surfaces exhibit naturally aligned dipoles, enhancing coupling.
• SDP optical properties show polarization-dependent modulation tunable over two orders of magnitude.

Conclusions:

• Near-surface Al-N DAPs are viable for quantum technologies.
• SDPs, particularly vanadium-based ones, offer novel pathways for enhanced dipole-dipole coupling.
• These near-surface defects are promising for developing hybrid quantum-classical interfaces and mediating information transfer.