title: Strong and Tunable Spin-Orbit Coupling in a Two-Dimensional Hole Gas in Ionic-Liquid Gated Diamond Devices.
abstract: Hydrogen-terminated diamond possesses due to transfer doping a quasi-two-dimensional (2D) hole accumulation layer at the surface with a strong, Rashba-type spin-orbit coupling that arises from the highly asymmetric confinement potential. By modulating the hole concentration and thus the potential using an electrostatic gate with an ionic-liquid dielectric architecture the spin-orbit splitting can be tuned from 4.6-24.5 meV with a concurrent spin relaxation length of 33-16 nm and hole sheet densities of up to 7.23 × 10(13) cm(-2). This demonstrates a spin-orbit interaction of unprecedented strength and tunability for a 2D hole system at the surface of a wide band gap semiconductor. With a spin relaxation length that is experimentally accessible using existing nanofabrication techniques, this result suggests that hydrogen-terminated diamond has great potential for the study and application of spin transport phenomena.
authors.affiliation: Department of Chemistry and Physics, La Trobe University , Melbourne, Victoria 3086, Australia.
authors.forename: Golrokh
authors.initials: G
authors.lastname: Akhgar
authors.affiliation: School of Physics, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors.forename: Oleh
authors.initials: O
authors.lastname: Klochan
authors.affiliation: School of Physics, The University of Melbourne , Melbourne, Victoria 3010, Australia.
authors.forename: Laurens H
authors.initials: LH
authors.lastname: Willems van Beveren
authors.affiliation: School of Physics, Monash University , Melbourne, Victoria 3800, Australia.
authors.forename: Mark T
authors.initials: MT
authors.lastname: Edmonds
authors.affiliation: Chair of Physical Chemistry II, Universität Erlangen-Nürnberg , Egerlandstraße 3, D-91058 Erlangen, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Maier
authors.affiliation: Department of Chemistry and Physics, La Trobe University , Melbourne, Victoria 3086, Australia.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Spencer
authors.affiliation: School of Physics, The University of Melbourne , Melbourne, Victoria 3010, Australia.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: McCallum
authors.affiliation: Department of Chemistry and Physics, La Trobe University , Melbourne, Victoria 3086, Australia.|Institute of Condensed Matter Physics, Universität Erlangen-Nürnberg , Staudt-Straße 1, D-91058 Erlangen, Germany.
authors.forename: Lothar
authors.initials: L
authors.lastname: Ley
authors.affiliation: School of Physics, University of New South Wales , Sydney, New South Wales 2052, Australia.
authors.forename: Alex R
authors.initials: AR
authors.lastname: Hamilton
authors.affiliation: Department of Chemistry and Physics, La Trobe University , Melbourne, Victoria 3086, Australia.
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Pakes
keywords: 2DHG; diamond; spin−orbit splitting; surface conductivity; weak antilocalization