Appearance of the dielectric instability and its coexistence with the superconductivity in ultrathin metallic filaments with decreasing diameter

Some dielectric instability appears before the superconducting (s/c) transition of Hg, In, Ga, Sn filaments when their diameters are decreased to 20 to 30 A. Above the s/c transition the differential conductivity of the filaments may be approximated by the formula σ = σsub(a) + σsub(b) exp [-E0 (T)/E], where the electric field E0 is equal to about 10 to 60 mV cm-1, and falls abruptly before the s/c transition. There are conductivity oscillations along E in the s/c transition region. The results are interpreted in terms of Peierls instability and charge - density wave (CDW) conductivity. (author)