Abstract

Graphene has a great potential for implementation of tunable field effect devices. The accessible and surface-exposed 2D electron gas offered by graphene provides indeed an ideal platform on which to tune, via application of an electrostatic gate, the coupling between adsorbates deposited on its surface. This situation is particularly interesting when the network of adsorbates can induce some electronic order within the underlying graphene substrate, such as magnetic or superconducting correlations. We have experimentally studied the case of macroscopic graphene transistors decorated with an array of superconducting tin nanoparticles, which induce via percolation of proximity effect a global but tunable 2D superconducting state which critical temperature Tc can be tuned by gate voltage. I will present other types of generic systems where molecules on top of graphene see their interaction modulated by the electrostatic field applied to the graphene layer. In that second type of experiment, we use Raman spectroscopy as the probe te measure the modulated interaction.