  Conventional magneto-oscillations of conductivity in three dimensions are
washed out as the temperature exceeds the spacing between the Landau levels.
This is due to smearing of the Fermi distribution. In two dimensions, in the
presence of two or more size-quantization sub-bands, there is an additional
type of magneto-oscillations, usually referred to as magneto-inter-sub-band
oscillations, which do not decay exponentially with temperature. The period of
these oscillations is determined by the condition that the energy separation
between the sub-bands contains an integer number of Landau levels. Under this
condition, which does not contain the Fermi distribution, the inter-sub-band
scattering rate is maximal. Here we show that, with only one sub-band,
high-temperature oscillations are still possible. They develop when the
electron spectrum is split due to the spin-orbit coupling. For these additional
oscillations, the coupling enters both, the period and the decay rate.
