Magnetoresistivity of bismuth in the phonon generation regime

The influence of quantization of the electron spectrum of bismuth in a magnetic field up to 150 kOe on the volt-ampere characteristics (VAC) is investigated in the phonon generation regime at helium and hydrogen temperatures. Oscillations of the transverse magnetoresistance are detected, whose extrema are located in the neighborhood of extrema of Shubnikov–de Haas (Sh–dH) oscillations. The oscillation amplitude in the phonon generation regime has an anomalous temperature dependence for the Sh–dH effect – it grows with the passage from helium to hydrogen temperatures. It is shown that the quantity Ec/H defining the coordinate of the break in the VAC depends significantly on the temperature and magnetic field, where it varies nonmonotonically in the magnetic field, similarly to the resistivity. An attempt is made to find the regularities of the effect of exciting current oscillations in the nonlinear regime E> Ec. It turns out that the dependence of the oscillation amplitude on the drift velocity duplicates the shape of the characteristic curve for the sound amplification coefficient. An analysis is made of the experimental results. In particular, it is shown that although it qualitatively describes some individual results the theory of the amplification of ultrasound is not able to give a consistent explanation of the whole set of observed effects.

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