  Spin-charge conversion via inverse spin Hall effect (ISHE) is essential for
enabling various applications of spintronics. The spin Hall response usually
follows a universal scaling relation with longitudinal electric resistivity and
has mild temperature dependence because elementary excitations play only a
minor role in resistivity and hence ISHE. Here we report that the ISHE of
metallic glasses shows nearly two orders of magnitude enhancements with
temperature increase from a threshold of 80-100 K to glass transition points.
As electric resistivity changes only marginally in the temperature range, the
anomalous temperature dependence is in defiance of the prevailing scaling law.
Such a giant temperature enhancement can be well described by a two-level
thermal excitation model of glasses and disappears after crystallization,
suggesting a new mechanism which involves unique thermal excitations of
glasses. This finding may pave new ways to achieve high spin-charge conversion
efficiency at room and higher temperatures for spintronic devices and to detect
structure and dynamics of glasses using spin currents.
