[institut] SCL seminar: High-Tc cuprates, M. Civelli

[Darko Tanaskovic]

Postovane koleginice i kolege,

pozivam vas da prisustvujete SCL seminaru koji ce u Sali biblioteke 
Instituta za fiziku u sredu 25. jula sa pocetkom u 12 casova odrzati

Dr. Marcello Civelli
Univesity of Paris Sud

"Superconducting gap versus psudogap in high-Tc cuprates: a cellular 
dynamical mean field theory perspective"

Abstract:
Although discovered only three years after the discovery of 
high-temperature superconductivity, the physical origin of the pseudogap 
phase of cuprate superconductors (observed above the critical 
temperature Tc) and its relation with the superconducting phase is still 
shrouded in mystery. I will present a theoretical study of the pseudogap 
and superconducting phases in a minimal model (the two-dimensional 
Hubbard Model) of cuprate superconductors, carried out by means of the 
cellular dynamical mean field theory (CDMFT). Our results show that, 
while the superconducting gap is associated to Cooper pair formation, 
the pseudogap rises from the parent Mott insulator upon doping and it is 
intrinsically a normal-state property, which competes with 
superconductivity for the same electron-states in momentum space. In 
particular, recent 16-cluster-site CDMFT results show that the pseudogap 
has an s-wave symmetry, different from the well-known d-wave symmetry of 
superconducting gap, and that therefore pseudo and superconducting gaps 
have different origin. I will finally show that these results imply a 
peculiar behavior in the B2g Raman response, as observed in many 
materials of the cuprate family.


Srdacan pozdrav,
Darko Tanaskovic