Correlated few-particle states in artificial bipolar molecule
  We investigate the ground and excited states of a bipolar artificial molecule composed of two vertically coupled quantum dots containing different type of carriers -- electrons and holes -- in equilibrium. The approach based on exact diagonalization is used and reveals an intricate pattern of ground-state angular momentum switching and a rearrangement of approximate single-particle levels as a function of the inter-dot coupling strength. 
Egidijus Anisimovas and F. M. Peeters