  Spatiotemporal properties of two-dimensional (2D) Hall-magnetohydrodynamic
turbulence at intermediate plasma $\beta=2$ are studied by means of Fast
Iterative Filtering, a new technique for the decomposition of nonstationary
nonlinear signals. Results show that the magnetic energy at sub-ion scales is
concentrated in perturbations with frequencies smaller than the ion-cyclotron
(IC) frequency and with polarization properties that are incompatible with both
kinetic Alfv\'en waves (KAWs) and IC waves. At higher frequencies, we clearly
identify signatures of both whistler waves and KAWs, however their energetic
contribution to the magnetic power spectrum is negligible. We conclude that the
dynamics of 2D Hall-MHD turbulence at sub-ion scales is mainly driven by
localized intermittent structures, with no significant contribution of wavelike
fluctuations.
