  A T-shaped field-effect transistor, made out of a pair of two-dimensional
electron gases, is modeled and studied. A simple numerical model is developed
to study the electron distribution vs. applied gate voltage for different gate
lengths. The model is then improved to account for depletion and the width of
the two-dimensional electron gases. The results are then compared to the
experimental ones and to some approximate analytical calculations and are found
to be in good agreement with them.
