Electron transport in crossed nanotubes with a point contact

The electron transport in a four-terminal nanodevice consisting of two crossed nanotubes is investigated in the framework of the Landauer-B\"uttiker formalism. The evident formula for the ballistic conductance of the device is found using a model of crossed conductive cylinders with a point contact between them. Sharp conductance dips stipulated by resonance scattering on the contact are shown to appear in the conductance of the first cylinder. The conductance between the cylinders has resonant behavior. The form and the position of resonant peaks are studied. Our results indicate that the form of asymmetric dips and peaks in the conductance differs from the well-known Fano line shape [Phys. Rev. 124, 1866 (1961)]. We have shown that the maximal value of the conductance between cylinders does not exceed a unit of the conductance quantum.