[institut] SCL Seminar: Jernej Mravlje, Monday, 26 December, 14:00
Darko Tanaskovic
tanasko at ipb.ac.rs
Tue Dec 20 11:32:42 CET 2016
Dear colleagues,
You are cordially invited to the SCL seminar of the Center for the Study
of Complex Systems, which will be held on Monday, 26 December 2016 at
14:00 in the library reading room “Dr. Dragan Popović" of the Institute
of Physics Belgrade. The talk entitled
Correlated-electron transport in hcp-Fe under extreme conditions present
in inner Earth Core
will be given by Dr. Jernej Mravlje ("Jozef Stefan" Institute,
Ljubljana, Slovenia).
Abstract of the talk:
The Earth's magnetic field is essential for the life as it protects the
ozone layer from the solar wind. The magnetic field exists due to the
geodynamo mechanism which is driven by convective processes in the
liquid iron external core. Sufficiently low thermal conductivity is
essential for the existence of the convection. Recently it has been
discovered that the electron-phonon interaction is less efficient than
believed earlier [1] and that the thermal conductivity is about 5 times
larger than assumed in geophysical models, which questions what ensures
the stability of the geodynamo. Work [2] suggested electron-electron
interactions could play an important role. It considered hcp-Fe,
believed to be the main constituent of the Earth's inner core, under 300
GPa and 6000K present there and found a non-Fermi liquid behavior and
large resistivity of the same magnitude as the electron-phonon one. We
repeated the same calculations more precisely [3] and found that the
hcp-Fe behaves as a Fermi liquid and that the calculated resistivity is
about 1/4th of the one found due to the electron-electron scattering due
to numerical mistakes in [2], which led to retraction of the paper. We
calculated also thermal conductivity. The effect of electron-electron
scattering on thermal conductivity is due to a breakdown of
Wiedemann-Franz law larger than the effect on electrical conductivity.
The calculated thermal conductivity is 540W/mK which is similar to the
one obtained from the electron-electron scattering 300W/mK [4], which
suggests electron-electron scattering plays a non-negligible role in the
dynamics of the Earth's core.
[1] M. Pozzo, C. Davies, D. Gubbins, and D. Alfe, Nature 485,
355,(2012).
[2] P. Zhang, R.E. Cohen, and K. Haule, Nature 517, 605 (2015).
[3] L. V. Pourovskii, J. Mravlje, A. Georges, S.I. Simak, I. A.
Abrikosov, arXiv:1603.02287 (2016)
[4] M. Pozzo, C. Davies, D. Gubbins, and D. Alfe, Earth and Planet. Sci.
Lett. 393, 159 (2014).
Best regards,
Darko Tanasković
More information about the institut
mailing list