Engineering the spin-orbit interaction in surface conducting diamond with a solid-state gate dielectric

Abstract

Hydrogen-terminated (H-terminated) diamond, when surface transfer doped, can support a sub-surface two-dimensional (2D) hole band that possesses a strong Rashba-type spin-orbit interaction. By incorporating a V2O5/Al2O3 bilayer gate dielectric in a diamond-based metal-oxide-semiconductor architecture, metallic surface conductivity can be maintained at low temperature, avoiding the carrier freeze out exhibited by devices with an Al2O3 gate dielectric alone. Hole densities of up to 2.5 × 1013 cm-2 are achieved by the electrostatic gating of the device, and the spin-orbit interaction strength can be tuned from 3.5 ± 0.5 meV to 8.4 ± 0.5 meV, with a concurrent reduction in the spin coherence len..