  We find that electrons in single-wall carbon nanotubes may propagate
substantial distances (tens of nanometers) under the metal contacts. We perform
four-probe transport measurements of the nanotube conductance and observe
significant deviations from the standard Kirchhoff's circuit rules. Most
noticeably, injecting current between two neighboring contacts on one end of
the nanotube, induces a non-zero voltage difference between two contacts on the
other end.
