Transport spectroscopy of lateral few electron quantum dots in a magnetic field

We have fabricated few electron lateral dots containing between 10 and 20 e lectrons. Single electron spectroscopic techniques have been used to invest igate the regime between v = 2 and v = 1, i.e., the transition from a spin unpolarized quantum dot to a spin polarized quantum dot. We compare the exp erimental results to non-interacting, Hartree-Fock and exact diagonalizatio n calculations. The comparison confirms that correlations are important in this regime. Spin-flips are found to be complex and rich phenomena involvin g a nontrivial spin polarization dependence on magnetic field and a resulti ng collapse of the Zeeman gap due to electronic correlations. (C) 1998 Else vier Science B.V. All rights reserved.