  We perform a multifractal detrended fluctuation analysis of the
magnetoconductance data of two standard types of mesoscopic systems: a
disordered nanowire and a ballistic chaotic billiard, with two different
lattice structures. We observe in all cases that multifractality is generally
present and that it becomes stronger in the quantum regime of conduction, i.e.,
when the number of open scattering channels is small. We argue that this
behavior originates from correlations induced by the magnetic field, which can
be characterized through the distribution of conductance increments in the
corresponding "stochastic time series," with the magnetic field playing the
role of a fictitious time. More specifically, we show that the distributions of
conductance increments are well fitted by $q$ Gaussians and that the value of
the parameter $q$ is a useful quantitative measure of multifractality in
magnetoconductance fluctuations.
