%0 Journal Article
%T Departure from the Wiedemann每Franz law in WP2 driven by mismatch in T-square resistivity prefactors
%J -
%D 2018
%R https://doi.org/10.1038/s41535-018-0136-x
%X The Wiedemann每Franz law establishes a link between heat and charge transport due to electrons in solids. The extent of its validity in the presence of inelastic scattering is a question raised in different contexts. Here we report on a study of the electrical, 考, and thermal, 百, conductivities in WP2 single crystals. The Wiedemann-Franz law holds at 2ˋK, but a downward deviation rapidly emerges upon warming. At 13ˋK, there is an exceptionally large mismatch between the Lorenz number and the Sommerfeld value. We show that this is driven by a fivefold discrepancy between the T-square prefactors of electrical and thermal resistivities, both caused by electron每electron scattering. This implies the existence of abundant small-scattering-angle collisions between electrons, due to strong screening. By quantifying the relative frequency of collisions conserving momentum flux, but degrading heat flux, we identify a narrow temperature window where the hierarchy of scattering times may correspond to the hydrodynamic regime
%U https://www.nature.com/articles/s41535-018-0136-x