alex_1.pdf (118.76 kB)
Download fileLorenz number in high Tc superconductors: evidence for bipolarons
preprint
posted on 2006-03-31, 15:28 authored by K.K. Lee, A.S. Alexandrov, W.Y. LiangStrong electron-phonon interaction in the cuprates has gathered support over the last decade in
a number of experiments. While phonons remain almost unrenormalised, electrons are transformed
into itinerent bipolarons and thermally excited polarons when the electron-phonon interaction is
strong. We calculate the Lorenz number of the system to show that the Wiedemann-Franz law
breaks down because of the interference of polaron and bipolaron contributions in the heat flow.
The model fits numerically the experimental Hall Lorenz number, which provides a direct evidence
for bipolarons in the cuprates.
History
School
- Science
Department
- Physics