AUTOCORRELATION FUNCTION AND MUTUAL INFORMATION FROM SHORT EXPERIMENTAL TIME-SERIES

A nonlinear dynamics of self-generated current oscillations in semi-insulating GaAs was studied by the reconstruction of an attractor from a short (14500 points) time series. Two methods of choosing of a time constant (tau) for this reconstruction are compared. One of them assumes tau to be an argument of the first zero of the autocorrelation function and the other takes tau as an argument of the first minimum of the mutual information. It is shown that for periodic oscillations both methods are equivalent, but for chaotic ones only the mutual information gives a time constant which does not depend on a time series used for calculations.