Strong and tunable spin-orbit coupling in a two-dimensional hole gas in ionic-liquid gated diamond devices

Golrokh Akhgar, Oleh Klochan, Laurens H. Willems Van Beveren, Mark T. Edmonds, Florian Maier, Benjamin J. Spencer, Jeffrey C. McCallum, Lothar Ley, Alex R. Hamilton, Christopher I. Pakes

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33 Citations (Scopus)


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 × 1013 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.

Original languageEnglish
Pages (from-to)3768-3773
Number of pages6
JournalNano Letters
Issue number6
Publication statusPublished - 8 Jun 2016


  • 2DHG
  • diamond
  • spin-orbit splitting
  • surface conductivity
  • weak antilocalization

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