[institut] Seminar

[Darko Tanaskovic]

Postovani,
u petak 8. oktobra u 11 casova u sali biblioteke 

Prof. Ross McKenzie
Department of Physics, University of Queensland, Brisbane, Australia

ce odrzati se predavanje pod naslovom

"Destruction of quasiparticles near the Mott metal-insulator transition".


Abstract:
The concept of quasiparticles is fundamental to quantum many-body
physics and to our understanding of the electronic properties of
elemental metals. However, there is considerable debate
about  the stability and quantum numbers (and even the existence)
of quasiparticles in a wide range of strongly correlated
electron materials[1]. Prominent examples include transition
metal oxides, high-Tc cuprate superconductors, and heavy fermion compounds.
The frequency dependent optical conductivity has proven to
be a powerful experimental probe in addressing these issues.
I will describe a recent combined theoretical and experimental
study of the low energy electrodynamics of charge carriers close to
the Mott metal-insulator transition in a quasi two-dimensional
organic charge-transfer salt [2].
The frequency dependence of the conductivity deviates significantly  from
the Drude model behavior, characteristic of
elemental metals.  There is a strong redistribution of spectral weight
 as the Mott transition is approached and  with temperature. The quasiparticles
only exist at relatively low energies
and their effective mass increases  considerably near the insulating phase.
A dynamical  mean-field-theory treatment of the relevant Hubbard model gives
a good  quantitative description of the experimental data [2].

[1] R.H. McKenzie, Nature Physics 3, 756 (2007).
[2] J. Merino, M. Dumm, N. Drichko, M. Dressel, and R. H. McKenzie,
 Phys. Rev. Lett. 100, 086404:1-4 (2008).


Srdacan pozdrav,
Darko Tanaskovic