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Semiconductor Physics Group

 

Graphene quantum dots

We have been working with the nobel-prize winning material graphene - single layers of carbon atoms which exhibit electronic properties relevant to a wide range of device applications and fundamental questions in condensed matter physics.

Graphene single quantum dotFigure 1: An AFM image of a graphene single quantum dot device.

In particular, our research focuses on the electrical properties of graphene nano-structures, such as nanoribbons and quantum dots (see Figure 1). The promise of long spin relaxation times makes graphene quantum dots - small islands of confined charge - particularly suited to quantum computing architectures that manipulate the spin degree of freedom. In order to probe the spin and charge dynamics of geometrically confined Dirac quasiparticles, we have performed magneto-transport measurements on a single dot and a series-coupled double dot at temperatures down to 100 mK and magnetic fields up to 12 T. AFM images of two devices are shown in Figures 1 (single quantum dot) and 2 (double quantum dot).

Graphene double quantum dotFigure 2: An AFM image of a graphene double quantum dot device.