Spin injection into multiwall carbon nanotubes across a molecular barrier*

Carbon-based materials such as graphene and carbon nanotubes are promising candidates for efficiently propagating spin information. It is mainly due to the weak spin-orbit coupling and to the weak hyperfine interactions present in those two nanomaterials. However, it remains challenging to inject spins directly from a ferromagnetic metal due to the so-called "impedance mismatch" problem. In this talk, I will present an experimental study concerning spin transport through large diameter multiwall carbon nanotubes functionalized by diazonium molecules and contacted by Co and Ni electrodes. I will show that the molecules form a conformational film around the nanotubes leading to injection resistance around 10 MΩ. I will then describe the magnetoresistance signal observed at low temperatures and its evolution as a function of bias voltage.