Naslov
The role of in-plane oxygens in optimally doped NCCO

Autori
Sunko, Denis K. ; Barišić, Slaven

Izvornik
Journal of superconductivity and novel magnetism (1557-1939) 20 (2007), 7; 623-627

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
ARPES; pseudogap; high-Tc; superconductivity

Sažetak
Within the framework of the three-band Hubbard (Emery) model of high-temperature superconductors, we find a new physical regime for the electron-doped compound NCCO at optimal doping. It is characterized by a strong renormalization of the bare copper-oxygen hopping, similar to the one occuring on the hole-doped side, and a low value of the effective copper-oxygen splitting. The effective copper-oxygen hopping appears smaller than the direct oxygen-oxygen hopping, which is not renormalized. After a zeroth-order fit of the Fermi surface is achieved, ARPES data throughout the zone are reproduced by adding a simple phenomenological weak-coupling antiferromagnetic perturbation of the conduction electrons. The dispersive antiferromagnons have low energy, but no long-range order. We can show that the experimental situation corresponds to a pseudogap across the whole Fermi surface. The wide dispersive features in NCCO ARPES spectra are analogous to the hump in BSCCO. The oxygen degree of freedom dominates the band structure of both NCCO and BSCCO, however in NCCO this cannot be demonstrated without simultaneously accounting for the antiferromagnetic scattering. The difference in Tc of the two compounds may be related to the difference in the calculated densities of states.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
Pozvano predavanje na 5th International Conference Stripes06, Rim, Italija, 17.12.-22.12.2006.

POVEZANOST RADA