Even-odd correlations in capacitance fluctuations of quantum dots

We investigate effects of short-range interactions on the addition spectra of quantum dots using a disordered Hubbard model. A correlation function S(q) is defined on the inverse compressibility versus filling data, and computed numerically for small lattices. Two regimes of interaction strength are identified: the even/odd fluctuations regime typical of Fermi-liquid ground states, and a regime of structureless S(q) at strong interactions. We propose to understand the latter regime in terms of magnetically correlated localized spins. © 1996 The American Physical Society.