Condensed Matter Physics Seminar

2 p.m., Thursday, September 22, 2005
Room 1201, Physics Building

Building the Perfect 2D Electron System in Silicon

Kevin Eng

(Laboratory for Physical Sciences and Dept. of Physics, University of Maryland)

Abstract: Typically two dimensional electron systems (2DES) in silicon are created by confining them at an interface between two different materials (e.g. MOSFETs). Unfortunately the silicon-dielectric interface contains inevitable disorder (e.g. dangling bonds on the silicon surface) which limits the electrons mobility. Such inherent disorder would be detrimental in the miniaturization towards atomic-scale electronic devices. We have recently developed a new high mobility 2DES, where an electric field is applied through an encapsulated vacuum cavity and induces electrons on a clean and atomically flat hydrogen-passivated Si surface. I will discuss our preliminary electron transport measurements (T < 4K) made on a H-Si(111) surface which have already shown electron mobilities a factor of 4 higher than previous Si(111) MOSFETs. We have made the first observation of the integer quantum Hall effect on a Si(111) surface, a particularly interesting 2DES because of the expected six-fold valley degeneracy and its extremely large screening parameter. I will conclude with a discussion of our future work and how this technique for gating air sensitive surfaces or materials through an encapsulated vacuum cavity has great potential in the development of atomic-scale electronic devices.

Host: Kane
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