Jure Kokalj published an article in the journal The Proceedings of the National Academy of Sciences (PNAS) titled “Electronic diffusion in a normal state of high-Tc cuprate YBa2Cu3O6+x.”

In it, he presented findings regarding electronic transport in the high-temperature superconducting cuprate YBa2Cu3O6+x at temperatures above the critical temperature Tc.
By using the Nernst-Einstein relation for heat and charge currents, previous measurements, and findings from numerical simulations, he managed to determine the behavior of the elusive electronic diffusion constant, average mean free path, and charge susceptibility.
The results revealed unexpectedly short mean free paths in the Mott-Ioffe-Regel limit region (l~a) already at temperatures above 200 K for low dopings, a significant violation of the so-called Planckian bound, and charge susceptibility with a significant dependence on temperature and doping. This affects the behavior of electrical conductivity, indicating that the electrical conductivity in these materials will only be understandable by simultaneously considering also thermodynamic quantities and not just within the framework of scattering mechanisms.