A schottky top-gated two-dimensional electron system in a nuclear spin free Si/SiGe heterostructure

We report on the realization and top-gating of a two-dimensional electron system in a nuclear spin free environment using (28)Si and (70)Ge source material in molecular beam epitaxy. Electron spin decoherence is expected to be minimized in nuclear spin-free materials, making them promising hosts for solid-state based quantum information processing devices. The two-dimensional electron system exhibits a mobility of 18000 cm(2)/(V s) at a sheet carrier density of 4.6 x 10(11) cm(-2) at low temperatures. Feasibility of reliable gating is demonstrated by transport through split-gate structures realized with pallidium Schottky top-gates which effectively control the two-dimensional electron system underneath. Our work forms the basis for the realization of an electrostatically defined quantum dot in a nuclear spin free environment.