  Quantum oscillations of the spin conductance through regular and chaotic 2D
quantum dots under the varying Rashba spin orbit interaction and at zero
magnetic field have been numerically calculated by summing up the spin
evolution matrices for classical transmitting trajectories. Fourier analysis of
these oscillations showed power spectra strongly dependent on the dot geometry.
For narrow rings the spectra are dominated by a single peak in accordance with
previous analytic results. In other geometries the spectra are represented by
multiple peaks for regular QD and quasicontinuum for chaotic QD.
