All Publications

  • Sample shape and boundary dependence of measured transverse thermal properties JOURNAL OF APPLIED PHYSICS Mumford, S., Paul, T., Kountz, E., Kapitulnik, A. 2020; 128 (17)

    View details for DOI 10.1063/5.0024253

    View details for Web of Science ID 000589711700001

  • Thermal diffusivity above the Mott-Ioffe-Regel limit PHYSICAL REVIEW B Zhang, J., Kountz, E. D., Levenson-Falk, E. M., Song, D., Greene, R. L., Kapitulnik, A. 2019; 100 (24)
  • Thermalization and possible signatures of quantum chaos in complex crystalline materials. Proceedings of the National Academy of Sciences of the United States of America Zhang, J., Kountz, E. D., Behnia, K., Kapitulnik, A. 2019


    Analyses of thermal diffusivity data on complex insulators and on strongly correlated electron systems hosted in similar complex crystal structures suggest that quantum chaos is a good description for thermalization processes in these systems, particularly in the high-temperature regime where the many phonon bands and their interactions dominate the thermal transport. Here we observe that for these systems diffusive thermal transport is controlled by a universal Planckian timescale [Formula: see text] and a unique velocity [Formula: see text] Specifically, [Formula: see text] for complex insulators, and [Formula: see text] in the presence of strongly correlated itinerant electrons ([Formula: see text] and [Formula: see text] are the phonon and electron velocities, respectively). For the complex correlated electron systems we further show that charge diffusivity, while also reaching the Planckian relaxation bound, is largely dominated by the Fermi velocity of the electrons, hence suggesting that it is only the thermal (energy) diffusivity that describes chaos diffusivity.

    View details for DOI 10.1073/pnas.1910131116

    View details for PubMedID 31515452