# Research

# NANO Centre of Excellence

The NANO centre of excellence consists of three research groups (EMAT, CMT, PLASMANT) with complementary expertise in the field of nanoscience and nanomaterials. A particular focus is on carbon, in the form of diamond, graphite, fullerenes or nanotubes.

The research focuses around the themes of structural and chemical characterization by means of electron microscopy, computer simulations of the growth of nano structures formed in plasmas or by laser interaction, theoretical modulation of nano structures and the study of their optical, magnetic and superconducting properties.

# Participating Research Groups

- Electron Microscopy for Materials Science (EMAT)

Department Physics - Condensed Matter Theory (CMT)

Department Physics - Plasma, Laser Ablation and Surface Modelling (PLASMANT)

Department Chemistry

### Publications and Covers

"Fluxonic cellular automata," M. V. MiloševiÄ‡a, G. R. Berdiyorov and F. M. Peeters Received 25 July 2007; accepted 5 September 2007; published online 19 November 2007 We propose a quantum cellular automata composed of nanostructured mesoscopic superconducting squares, where the logic states are defined by two trapped vortices in a 2 X 2 blind hole matrix. We present the functioning logic gate based on this fluxonic cellular automata, where the logic operations are verified through theoretical simulations within the Ginzburg-Landau formalism. The input signals are defined using the vortex interaction with current loops placed on top of the two diagonal blind holes of the input cell. The readout technology may be chosen from a large variety of modern vortex imaging methods, transport, and local density of states measurements. © 2007 American Institute of Physics. [DOI: 10.1063/1.2813047] Download: Fluxonic cellular automata (pdf - 0.5Mb) |

“A three-dimensional model for artificial atoms and molecules: influence of substrate orientation and magnetic field dependence” V. Mlinar and F. M. Peeters A full three-dimensional model for the calculation of the electronic structure of semiconductor quantum dots (QD) and molecules (QDM) grown on high index surfaces and/or in the presence of an external magnetic field is presented. The strain distribution of the dots is calculated using continuum elasticity and singe-particle states are extracted from the nonsymmetrized eight-band k?p theory. The model properly takes into account the effects of different substrate orientation by rotation of the coordinate system in such a way that one coordinate coincides with the growth direction, whereas the effects of a tilted external magnetic field are taken into account through the Zeeman effect and employing a gauge invariant scheme based on Wilson’s formulation of lattice gauge theory. We point out the role of piezoelectricity for InAs/GaAs QDs grown on [11k], where k = 1,2,3,4,5,7,9 and for QDMs containing eight InAs/GaAs QDs grown on [11l], where l = 1,2,3. We predict the variation of the transition energies of the QDM as a function of substrate orientation and interdot distances in the molecule. We address the magnetic field direction dependent variation of the electronic properties of QD and QDM. |

### Nano in the Press

- Technologie op nanoschaal maar op mensenmaat (pdf - 1.2Mb)

ALFABETA - nummer 70

### Vacancies

Available vacancies at the Centre of Excellence NANO are listed via the websites of the participating research groups:

- Electron Microscopy for Materials Science (EMAT)
- Condensed Matter Theory (CMT)
- Plasma, Laser Ablation and Surface Modelling (PLASMANT)

Available vacancies at the participating research groups can be found via the academic, administrative & technical staff vacancies of the University of Antwerp.