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

physica status solidi (RRL) - Rapid Research Letters (Impact Factor: 2.34). 03/2009; 3(2-3). DOI: 10.1002/pssr.200802275
Source: arXiv

ABSTRACT 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.

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