Calculation of the few-electron states in semiconductor carbon nanotube quantum dots by exact diagonalisation

The 3 and 4-electron states of a gated semiconducting carbon nanotube quantum dot are calculated by exact diagonalisation of a modified effective mass Hamiltonian. A typical nanotube quantum dot is examined and the few-electron states are Wigner molecule-like. The exact diagonalisation method and the rate of convergence of the calculation are discussed.