Confinement in Graphene Nanostructures CONGRAN

• Applicant: Professor Dr. Guido Burkard
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2010 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 162680136

Tunable graphene-based quantum dots offer unique advantages in comparison to conventional quantum dots made from semiconductor heterostructures, namely longer spin coherence times, novel spin effects, and the potential for a size reduction leading to operation of quantum dots at higher temperatures. However, transferring the conventional top gate technology to define tunable graphene-based quantum dots is nontrivial due to Klein tunneling. The project aims for the implementation and investigation of the three approaches for tunable confinement in graphene which are presently foreseen, namely combining lateral confinement with top gates, biased bilayer systems and magnetic confinement. Based on these results, graphene-based quantum dots will be tailored which potentially rely on all three confinement schemes and are optimized for the investigation of spin effects and operation at elevated temperatures. At the beginning of the project, each experimental partner will implement one confinement scheme, while the theory partners work on development of relevant models for the graphene based quantum dots, namely energy spectra, effects of disorder and interactions, and spin effects. These results will form the basis for the subsequent investigations of spin relaxation and pin decoherence, spin blockade and gdots at elevated temperatures.

• DFG Programme: Research Grants
• International Connection: Belgium, Netherlands, Switzerland
• Participating Persons: Professor Dr. Klaus Ensslin; Professor Dr. Francois M. Peeters; Dr. Lieven Vandersypen