Nonlocal spin transport in single walled carbon nanotube networks

Spin transport in carbon-based materials has stimulated much interest due to their ballistic conductance and a long phase coherence length. While much research has been conducted on individual carbon nanotubes, current growth and placement techniques are incompatible with large-scale fabrication. Here, we report on nonlocal spin injection and detection in single-walled carbon nanotube networks. We observe spin transport over a distance of 1 \ensuremath{\mu}m and extract a spin diffusion length of 1.6--2.4 \ensuremath{\mu}m with an injected spin polarization from CoFe into nanotube network of 18$%$--41$%$. Our observations demonstrate that spin transport is possible in carbon nanotube networks due to the formation of natural tunnel barriers between nanotubes and metallic contacts.