The quantum effects in conductivity of low-dimensional nanostructure prepared from perfect crystalline films could be the basis for a new generation of nanoelectronics devices provided that at least one of the nanostructure dimensions corresponds to the electron Fermi-wavelength. Changes of electrical resistance are proportional to the fundamental quant of resistance (which is about 13k) in these ballistic low-dimensional conductors. The value of resistance change depends on the conductor cross-section.In this work, the electrical resistance of short and long bridges of different widths made from large-grained thin âismuth films was measured in order to determine the quantum transport of conductivity electrons along the (0001) crystal planes that are parallel to the SiO₂/Si substrate. The following conclusions can be drawn:

• for the bridges 2000nm long, the electrical resistance as a function of width changes in accordance with the classical size effect.
• for the bridges 400nm long, whose length is comparable with the mean grain size, electrical resistance jumps connected with conductivity electron quantization are clearly seen against the background of the classical size effect.

The bridge width dependence on jump heights is in good agreement with the estimations done for these experimental conditions. The oscillations of the specific electrical resistance of the bridges with the amplitude about 500-600 mW cm, which is more than 100%, correspond to the jumps of electrical resistance. The oscillations period of the specific electrical resistance of the bridges is found to be 50nm. On the average, the presence of one grain boundary on average in the structure of short bridges does not lead to complete scattering and the loss of electron wave coherence.