Departure from the Wiedemann–Franz law in WP2 driven by mismatch in T-square resistivity prefactors

Jaoui A, Fauque B, Rischau CW, Subedi A, Fu C, Gooth J, Kumar N, Suess V, Maslov DL, Felser C, Behnia K (2018)

Publication Type: Journal article

Publication year: 2018

Journal

npj Quantum Materials Springer Nature

Book Volume: 3

Article Number: 64

Journal Issue: 1

DOI: 10.1038/s41535-018-0136-x

Abstract

The Wiedemann–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, σ, and thermal, κ, conductivities in WP2 single crystals. The Wiedemann-Franz law holds at 2 K, but a downward deviation rapidly emerges upon warming. At 13 K, 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–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.

Involved external institutions

Max-Planck-Institut für Chemische Physik fester Stoffe (MPI CPfS) / Max Planck Institute for Chemical Physics of Solids DE Germany (DE) University of Pittsburgh Medical Center (UPMC) US United States (USA) (US) École Polytechnique - Université Paris-Saclay FR France (FR) PSL Research University / Université de recherche Paris Sciences et Lettres FR France (FR) University of Florida US United States (USA) (US)

How to cite

APA:

Jaoui, A., Fauque, B., Rischau, C.W., Subedi, A., Fu, C., Gooth, J.,... Behnia, K. (2018). Departure from the Wiedemann–Franz law in WP2 driven by mismatch in T-square resistivity prefactors. npj Quantum Materials, 3(1). https://doi.org/10.1038/s41535-018-0136-x

MLA:

Jaoui, Alexandre, et al. "Departure from the Wiedemann–Franz law in WP2 driven by mismatch in T-square resistivity prefactors." npj Quantum Materials 3.1 (2018).

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