Electron–Electron Correlations in Square-Well Quantum Dots: Direct Energy Minimization Approach

Electron–electron correlations in two-dimensional square-well quantum dots are investigated using the direct energy minimization scheme. Searches for groundstate charges and spin configurations are performed with varying the sizes of dots and the number of electrons. For a two-electron system, a standout difference between the configurations with and without counting correlation energy is demonstrated. The emergence and melting of Wigner-molecule-like structures arising from the interplay between the kinetic energy and Coulombic interaction energy are described. Electron–electron correlation energies and addition energy spectra are calculated, and special electron numbers related to peculiar effects of the square well are extracted.