Spin-orbit interaction in a two-dimensional hole gas at the surface of hydrogenated diamond.

Edmonds, Mark T; Willems van Beveren, Laurens H; Klochan, Oleh; Cervenka, Jiri; Ganesan, Kumar; Prawer, Steven; Ley, Lothar; Hamilton, Alexander R et al. · Nano Lett · 2015

basic_science · Level V

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Abstract

Hydrogenated diamond possesses a unique surface conductivity as a result of transfer doping by surface acceptors. Yet, despite being extensively studied for the past two decades, little is known about the system at low temperature, particularly whether a two-dimensional hole gas forms at the diamond surface. Here we report that (100) diamond, when functionalized with hydrogen, supports a p-type spin-3/2 two-dimensional surface conductivity with a spin-orbit interaction of 9.74 ± 0.1 meV through the observation of weak antilocalization effects in magneto-conductivity measurements at low temperature. Fits to 2D localization theory yield a spin relaxation length of 30 ± 1 nm and a spin-relaxation time of ∼ 0.67 ± 0.02 ps. The existence of a 2D system with spin orbit coupling at the surface of a wide band gap insulating material has great potential for future applications in ferromagnet-semiconductor and superconductor-semiconductor devices.