Abstract
Strain tuning through the Lifshitz point, where the Van Hove singularity of the electronic spectrum crosses the Fermi energy, is expected to cause a change in the temperature dependence of the electrical resistivity from its Fermi liquid behavior to , a behavior consistent with experiments by Barber et al. [Phys. Rev. Lett. 120, 076602 (2018)]. This expectation originates from the same multiband scattering processes with large momentum transfer that were recently shown to account for the linear in resistivity of the strange metal . In contrast, the thermal resistivity , where is the thermal conductivity, is governed by qualitatively distinct processes that involve a broad continuum of compressive modes, i.e., long-wavelength density excitations in Van Hove systems. While these compressive modes do not affect the charge current, they couple to thermal transport and yield . As a result, we predict that the Wiedemann-Franz law in strained should be violated with a Lorenz ratio . We expect this effect to be observable in the temperature and strain regime where the anomalous charge transport was established.
- Received 6 August 2021
- Revised 11 February 2022
- Accepted 14 February 2022
DOI:https://doi.org/10.1103/PhysRevB.105.115113
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