Anomalously Suppressed Thermal Conduction by Electron-Phonon Coupling in Charge-Density-Wave Tantalum Disulfide

Huili Liu, Chao Yang, Bin Wei, Lei Jin, Ahmet Alatas, Ayman Said, Sefaattin Tongay, Fan Yang, Ali Javey, Jiawang Hong, Junqiao Wu

Research output: Contribution to journalArticle

Abstract

Charge and thermal transport in a crystal is carried by free electrons and phonons (quantized lattice vibration), the two most fundamental quasiparticles. Above the Debye temperature of the crystal, phonon-mediated thermal conductivity (κL) is typically limited by mutual scattering of phonons, which results in κL decreasing with inverse temperature, whereas free electrons play a negligible role in κL. Here, an unusual case in charge-density-wave tantalum disulfide (1T-TaS2) is reported, in which κL is limited instead by phonon scattering with free electrons, resulting in a temperature-independent κL. In this system, the conventional phonon–phonon scattering is alleviated by its uniquely structured phonon dispersions, while unusually strong electron-phonon (e-ph) coupling arises from its Fermi surface strongly nested at wavevectors in which phonons exhibit Kohn anomalies. The unusual temperature dependence of thermal conduction is found as a consequence of these effects. The finding reveals new physics of thermal conduction, offers a unique platform to probe e-ph interactions, and provides potential ways to control heat flow in materials with free charge carriers. The temperature-independent thermal conductivity may also find thermal management application as a special thermal interface material between two systems when the heat conduction between them needs to be maintained at a constant level.

Original languageEnglish (US)
Article number1902071
JournalAdvanced Science
Volume7
Issue number11
DOIs
StatePublished - Jun 1 2020

Keywords

  • charge density waves
  • electron-phonon coupling
  • lattice thermal conductivity
  • tantalum disulfide

ASJC Scopus subject areas

  • Medicine (miscellaneous)
  • Chemical Engineering(all)
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)
  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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    Liu, H., Yang, C., Wei, B., Jin, L., Alatas, A., Said, A., Tongay, S., Yang, F., Javey, A., Hong, J., & Wu, J. (2020). Anomalously Suppressed Thermal Conduction by Electron-Phonon Coupling in Charge-Density-Wave Tantalum Disulfide. Advanced Science, 7(11), [1902071]. https://doi.org/10.1002/advs.201902071