Correlation-induced inhomogeneity in circular quantum dots

Amit Ghosal 1, A. D. Guclu 2, C. J. Umrigar 2, Denis Ullmo 1, 3, Harold U. Baranger 1

Nature Physics 2 (2006) 336-340

Physical properties of the ``electron gas'' -- in which conduction electrons interact via Coulomb forces but the ionic potential is neglected -- change dramatically depending on the balance between the strength of the kinetic energy and the Coulomb repulsion. The limiting cases are well understood: For weak interactions (high density), the system behaves as a Fermi liquid, with delocalized electrons. In contrast, in the strongly interacting limit (low density), the electrons localize and become ordered in a Wigner crystal phase. The physics at intermediate densities is phenomenally rich and remains a subject of fundamental research. Here we study the intermediate density electron gas confined to a circular quantum dot. By using accurate quantum Monte Carlo techniques, we show that the correlation induced by increasing interaction strength smoothly causes, first, ring structure and, then, angular modulation, without any signature of a sharp transition or even a cross-over in this density regime.

  • 1. Duke Physics,
    Duke University
  • 2. Laboratory of Atomic and Solid State Physics (LASSP),
    Cornell University
  • 3. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
    CNRS : UMR8626 – Université Paris XI - Paris Sud