Dr. Amit Ghosal
UCLA Physics & Astronomy

Title:
Toward Strong Interactions in Circular Quantum Dots: Correlation Induced Inhomogeneity

Abstract:
Physical properties of the 'electron gas', which describes conduction electrons interacting via Coulomb forces in a solid, change dramatically depending on the balance between the strength of the kinetic energy and the Coulomb repulsion. The limiting cases are well understood: For very 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, causing a transition to a Wigner crystal phase. The physics at intermediate densities is phenomenally rich and remains a subject of fundamental research. In this talk, we present a study of the intermediate density electron gas (up to r_s=20) confined to a circular quantum dot containing up to 20 electrons. By using an accurate quantum Monte Carlo technique, we show that the correlation induced by increasing interaction strength smoothly causes, first, ring structure and, then, angular modulation without any signature of a cross-over. Dots with smaller number of electrons are typically more affected by correlation effects.