Research in Tsukuba
From Physical Review Focus
As silicon chips shrink ever smaller, understanding their operation at the atomic scale becomes more important. In the 12 January Physical Review Letters, researchers describe an imaging technique that directly reveals, with nanoscale resolution, how current-carrying charges move in semiconductor crystals. Although the first results agree with standard theory, the method should prove useful as chip designers move to still smaller devices, with less easily predictable behavior.
The standard theory describing how far electrons and holes diffuse in a p-n junction, depending on the voltage, is based on measurements of the total current in the circuit, not on direct observations of the charges themselves. To see if a junction’s microscopic behavior agrees with this theory, Hidemi Shigekawa of the University of Tsukuba in Japan and his colleagues combined scanning tunneling microscopy (STM) with laser illumination to map out the presence of charge carriers. Previous studies combined light with STM to probe semiconductor properties, but none have gotten a direct picture of the carrier density. And none have looked at the semiconductor while current flowed through it.
Read the full story: Current Under a Microscope
From NPI Center
Kyowa Hakko, the amino acid manufacturing leader who has introduced a wide range of fermentation-based amino acids, developed the white paper kit in conjunction with Kyowa’s newly formed Product Development Research Center in Tsukuba, Japan. The technical reports and references will provide an overview of the latest science on amino acids and related compounds.