Addition spectra of chaotic quantum dots: Interplay between interactions and geometry

We investigate the influence of interactions and geometry on ground states of clean chaotic quantum dots using the self-consistent Hartree-Fock method . We find two distinct regimes of interaction strength: While capacitive en ergy fluctuations delta chi follow approximately a random matrix prediction for weak interactions, there is a crossover to a regime where delta chi is strongly enhanced and scales roughly with interaction strength. This enhan cement is related to the rearrangement of charges into ordered states near the quantum dot edge. This effect is nonuniversal depending on the shape an d the size of the dot. It may provide insight into recent experiments on st atistics of Coulomb blockade peak spacings.