Wigner Localization in Quantum Dots from Kohn-Sham Density Functional Theory Without Symmetry Breaking

We address low-density two-dimensional circular quantum dots with spin-restricted Kohn-Sham density functional theory. By using an exchange-correlation functional that encodes the effects of the strongly correlated regime (and that becomes exact in the limit of infinite correlation), we are able to reproduce characteristic phenomena such as the formation of ring structures in the electronic total density, preserving the fundamental circular symmetry of the system. The observation of this and other well-known effects in Wigner-localized quantum dots such as the flattening of the addition energy spectra has until now only been within the scope of other, numerically more demanding theoretical approaches. © 2014 American Physical Society.