Low Temperature Physics: 41, 396 (2015); https://doi.org/10.1063/1.4919377
Физика Низких Температур: Том 41, Выпуск 5 (Май 2015), c. 508-513    ( к оглавлению , назад )

Electronic and magnetic properties of graphite quantum dots

Hazem Abdelsalam1,2, T. Espinosa-Ortega3, and Igor Luk’yanchuk1

1University of Picardie, Laboratory of Condensed Matter Physics, Amiens 80039, France
E-mail: lukyanc@ferroix.net

2Department of Theoretical Physics, National Research Center, Cairo 12622, Egypt

3Division of Physics and Applied Physics, Nanyang Technological University, Nanyang 637371, Singapore

Received January 15, 2015


We study the electronic and magnetic properties of multilayer quantum dots (MQDs) of graphite in the nearest-neighbor approximation of tight-binding model. We calculate the electronic density of states and orbital susceptibility of the system as function of the Fermi level location. We demonstrate that properties of MQD depend strongly on the shape of the system, on the parity of the layer number and on the form of the cluster edge. The special emphasis is given to reveal the new properties with respect to the monolayer graphene quantum dots. The most interesting results are obtained for the triangular MQD with zig-zag edge at near-zero energies. The asymmetrically smeared multipeak feature is observed at Dirac point within the size-quantized energy gap region, where monolayer graphene flakes demonstrate the highly-degenerate zero-energy state. This feature, provided by the edge-localized electronic states results in the splash-wavelet behavior in diamagnetic orbital susceptibility as function of energy.

PACS: 75.75.–c Magnetic properties of quantum dots;
PACS: 73.21.La Electron states and collective excitation in quantum dots.

Key words: multilayer quantum dots, tight-binding model, graphite.

Published online: March 23, 2015