  We study the interference of interacting electrons in toroidal single-wall
carbon nanotubes coupled to metallic electrodes by tunnel junctions. The dc
conductance shows resonant features as a function of the gate voltage and the
magnetic field. The conductance pattern is determined by the interaction
parameter, which in turn can be cross-checked against the exponents governing
the transport at high temperatures. The coordinate dependence of the
conductance reflects electron correlations in one-dimensional space.
