HIGH-FIELD MAGNETORESISTANCE OSCILLATIONS IN NBSE3

We report on magnetoresistance experiments performed on NbSe3 with pulsed magnetic fields (i) up to 37 teslas in the temperature range from 2K to 24K and (ii) up to 52 teslas at a temperature of 2K. In addition to the low field oscillations associated with the Landau levels n greater-than-or-equal-to 1, a huge oscillation is observed at 38 teslas in the ultra quantum limit. The whole set of experimental data are well accounted for by the Shubnikov-de Haas (SDH) model : the 38 teslas oscillation is in agreement with the predicted value for the 0+ Landau level, taking into account the Zeeman splitting. Moreover, the analysis of the temperature dependence of the SDH oscillation amplitude recorded during the 37 teslas experiments yield consistent values for both the cyclotron mass and the Dingle temperature.