This award will enable Dr. Craig Van Degrift of the National Bureau of Standards, Washington, D.C., to conduct research at the Electrotechnical Laboratory (ETL) in Tsukuba, Japan, for twelve months. Dr. Van Degrift will collaborate with members of the group of Dr. Katsunori Shida in a study of corrections to the quantum Hall effect that depend upon such phenomena as electron concentration in heterostructures, and the size of experimental samples. The quantum Hall effect, which occurs in certain materials at low temperatures and high magnetic fields, causes semiconductors to exhibit a quantized magnetically induced resistance, the value of which can be used to determine certain physical constants. Dr. Van Degrift has extensive experience with the quantum Hall effect, and its application to fundamental measurements, at the National Bureau of Standards. Working at ETL, he would be able to take advantage of ETL's own experience, as well as their extensive facilities for the fabrication of test devices. Close cooperation between researchers of ETL and of NBS, both organizations responsible for the maintenance of measurements standards in their respective countries, would be mutally beneficial.
