Proximity-Induced Electronic and Magnetic Effects in Phthalocyanine/Graphene/h-BN Heterostructures*

Graphene is an ideal building block of complex heterostructures. Normally, in proximity to molecular thin films its mobility is compromised. However, our recent results show that graphene in proximity to a molecular thin film of Copper Phthalocyanine (CuPc) preserves its mobility while transferring an important amount of electrons to CuPc (~10^12/cm^2). Additionally, we have found that weak localization in bilayer graphene is restored by the presence of the CuPc molecules. 

Our heterostructures are fabricated by transferring graphene on hexagonal boron nitride (h-BN) and depositing through thermal evaporation of a phthalocyanine thin film. We plan to perform experiments using Manganese Phthalocyanine (MnPc), a similar molecule which has a higher magnetic moment than CuPc and an unpaired electron of S=3/2. MnPc is one of the few Pcs to develop long range magnetic order at low temperatures. We expect to see in electronic transport experiments on a MnPc / graphene / h-BN heterostructure signature of the proximity effects with a ferromagnetic molecular thin film, measured in the quantum coherence regime.