## Daniel C. Tsui

**Arthur LeGrand Doty Professor of Electrical Engineering**

Ph.D. 1967, University of Chicago

My field of research activity is the electrical properties of thin
films and microstructures of semiconductors and solid-state physics. My
current research at Princeton is on the fundamental properties of
electronic materials, especially conduction in ultrasmall structures,
transport through heterojunctions, heterojunction transistors, and
quantum physics of electronic materials in strong magnetic fields and
low temperatures, in particular, the quantum Hall regime (see figure
below).

Before coming to Princeton sixteen years ago I had thirteen years of
research experience in solid-state electronics at Bell Laboratories.

*A demonstration of the fractional quantum Hall
effect discovered by Tsui and Störmer, for which they were awarded the
Nobel Prize
in physics in 1998. Plotted are the diagonal(R) and
Hall (R*_{H}) resistances of a two-dimensional electron gas at
the interface of two semiconductors, as a function of magnetic field
applied normal to the plane. The dashed diagonal line represents the
classical Hall resistance, and the full drawn diagonal stepped curve
the experimental results. The magnetic fields causing the steps are
marked with arrows at which the diagonal resistance R is expected to be
zero and absolute zero temperature. The step marked 1/3 was the first
fraction discovered by Störmer and Tsui.