Hydrogen-terminated diamond possesses an intriguing p-type surface conductivity which is induced via thermodynamically driven electron transfer from the diamond surface into surface acceptors such as atmospheric adsorbates, a process called surface transfer doping. High electron affinity transition metal oxides (TMOs) including MoO3 and V2O5 have been shown to be highly effective solid-state surface acceptors for diamond, giving rise to a sub-surface two-dimensional (2D) hole layer with metallic conduction. In this work, low temperature magnetotransport is used as a tool to show the presence of a Rashba-type spin-orbit interaction with a high spin-orbit coupling of 19.9 meV for MoO3 doping and 22.9 meV for V2O5 doping, respectively, through the observation of a transition in the phase-coherent backscattering transport from weak localization to weak antilocalization at low temperature. Surface transfer doping of diamond with TMOs provides a 2D hole system with spin-orbit coupling that is over two times larger than that reported for diamond surfaces with atmospheric acceptors, opening up possibilities to study and engineer spin transport in a carbon material system.

中文翻译：

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氢封端金刚石表面过渡金属氧化物引起的强自旋轨道相互作用

氢封端金刚石具有有趣的 p 型表面电导率，这是通过热力学驱动的电子从金刚石表面转移到表面受体（如大气吸附物）而诱导的，这一过程称为表面转移掺杂。包括 MoO3 和 V2O5 在内的高电子亲和性过渡金属氧化物 (TMO) 已被证明是金刚石的高效固态表面受体，可产生具有金属导电性的亚表面二维 (2D) 空穴层。在这项工作中，低温磁传输被用作一种工具，以显示 Rashba 型自旋轨道相互作用的存在，MoO3 掺杂的自旋轨道耦合分别为 19.9 meV，V2O5 掺杂的自旋轨道耦合分别为 22.9 meV，通过观察低温下相位相干反向散射传输从弱定域到弱反定域的转变。金刚石与 TMO 的表面转移掺杂提供了具有自旋轨道耦合的 2D 孔系统，该系统比具有大气受体的金刚石表面所报道的大两倍以上，为研究和设计碳材料系统中的自旋输运开辟了可能性。