Quantum dots based on parabolic quantum wells: importance of electronic   correlations
  We present measurements and theoretical interpretation of the magnetic field dependent excitation spectra of a two-electron quantum dot. The quantum dot is based on an Al$_x$Ga$_{1-x}$As parabolic quantum well with effective $g^\star$-factor close to zero. Results of tunneling spectroscopy of the four lowest states are compared to exact diagonalization calculations and a generalized Heitler--London approximation and good agreement is found. Electronic correlations, associated with the formation of an H$_2$-type Wigner molecule, turn out to be very important in this system. 
T. Ihn, C. Ellenberger, C. Yannouleas, U. Landman, K. Ensslin, D.   Driscoll, and A.C. Gossard