We report on the realization and top-gating of a two-dimensional electron system in a nuclear spin free environment using 28Si and 70Ge 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 cm2/Vs at a sheet carrier density of 4.6E11 cm-2 at low temperatures. Feasibility of reliable gating is demonstrated by transport through split-gate structures realized with palladium 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.
@article{arxiv.0901.2433,
title = {A Schottky top-gated two-dimensional electron system in a nuclear spin free Si/SiGe heterostructure},
author = {J. Sailer and V. Lang and G. Abstreiter and G. Tsuchiya and K. M. Itoh and J. W. Ager and E. E. Haller and D. Kupidura and D. Harbusch and S. Ludwig and D. Bougeard},
journal= {arXiv preprint arXiv:0901.2433},
year = {2009}
}