Interacting Electrons in Disordered Potentials: The Inverse Compressibility

The inverse compressibility, i.e., the change in the chemical potential as the number of particles in the sample is changed, is studied for a small quantum dot. It is found that the inverse compressibility behaves differently for different values of disorder and electron-electron interactions. For weak interactions or strong disorder one may understand this behavior in the framework of a random matrix theory.