Events

Seminar of International Laboratory of High Magnetic Fields and Low Temperatures PAS

Pseudogap in high-Tc superconductors: Evidence for the Local Pair model in comparison with ARPES results

A. L. Solovjov

B. I.Verkin Institute for Low Temperature Physics and Engineering of National, Academy of Science of Ukraine

Up to now there is no proper understanding of the coupling mechanism in high-Tc superconductors (HTS's) which allows the Cooper pairing at such high temperatures (T_c > 100 K). Another unusual property of the HTS's is a pseudogap (PG) which is characterized by the reduced density of states (DOS) at the Fermi level and occurs below the PG temperature T*>>T_c. It is believed at present that proper understanding of the PG has to shed more light at the pairing problem. But the physics behind the PG also remains very controversial. At present the models, which stay for the superconducting pairing as a reason for the PG, become more popular. To describe the temperature dependence of the PG the Local Pair (LP) model was developed. In accordance with the model the local pairs have to appear in the HTS's just below T*. Recently it was found that there are two additional characteristic temperatures T_pair and TS just in the interval between T* and Tc. The similar results come from ARPES experiments and can likely be explained by the rearrangement of the Fermi surface.