SPIN-ENSEMBLE DENSITY-FUNCTIONAL THEORY FOR INHOMOGENEOUS QUANTUM HALL SYSTEMS

We have developed an ensemble density-functional theory that includes spin degrees of freedom for non-uniform quantum Hall systems. We have applied this theory using a local-spin-density approximation to study the edge reconstruction of parabolically confined quantum dots. For a Zeeman splitting below a certain critical value, the edge of a complet ely polarized maximum density droplet reconstructs into a spin-unpolar ized structure. For larger Zeeman splittings, the edge remains polariz ed and develops an exchange hole.