title: Spin-orbit interaction in a two-dimensional hole gas at the surface of hydrogenated diamond.
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.
authors.affiliation: Department of Physics, La Trobe University , Bundoora, Victoria 3086, Australia.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Edmonds
authors.forename: Laurens H
authors.initials: LH
authors.lastname: Willems van Beveren
authors.forename: Oleh
authors.initials: O
authors.lastname: Klochan
authors.forename: Jiri
authors.initials: J
authors.lastname: Cervenka
authors.forename: Kumar
authors.initials: K
authors.lastname: Ganesan
authors.forename: Steven
authors.initials: S
authors.lastname: Prawer
authors.forename: Lothar
authors.initials: L
authors.lastname: Ley
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Hamilton
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Pakes
keywords: 2DHG; Diamond; spin−orbit interaction; surface conductivity