LINEAR-CHAIN OF COUPLED QUANTUM DOTS

A linearly coupled chain of spin-polarized quantum dots is investigate d under the condition that the number of electrons is equal to or less than the number of the dots. The chemical potential of the system, mu (N) = E(N) - E(N-1), satisfies (mu(N) + mu(Nt+2-N))/2 approximate to V + 2t [N, N-t, V, E(N), and t are the number of electrons, the number of dots, the strength of nearest-neighbor electron-electron interactio ns, the total ground-state energy, and the hopping integral between tw o adjacent dots]. This property will be reflected in the spacing betwe en the conductance peaks. The electron-density structures are determin ed using a quantum Monte Carlo method. As the number of electrons is v aried, several correlated structures are found that are commensurate/i ncommensurate with the periodic dot system. Hartree-Fock theory fails to predict the correct electronic structures of this system because se veral nearly degenerate solutions exist.