We report on the observation of a non-local voltage in a ballistic one-dimensional conductor, realized by a single-wall carbon nanotube with four contacts. The contacts divide the tube into three quantum dots which we control by the back-gate voltage Vg. We measure a large \emph{oscillating} non-local voltage Vnl as a function of Vg with zero mean. Though a classical resistor model can account for a non-local voltage including change of sign, it fails to describe the magnitude properly. The large amplitude of Vnl is due to quantum interference effects and can be understood within the scattering-approach of electron transport.
@article{arxiv.0710.0365,
title = {Large oscillating non-local voltage in multi-terminal single wall carbon nanotube devices},
author = {G. Gunnarsson and J. Trbovic and C. Schonenberger},
journal= {arXiv preprint arXiv:0710.0365},
year = {2009}
}