Unusual or Usual Isotope Effect in HTSCs?!?

The isotope effect (IE) on Tc of optimally doped HTSCs (α=dlnTc/dlnM <0.1) is small in comparison with the conventional BCS superconductors (α~0.5), an evidence that usually used against the phonon mediated pairing in HTSCs. However, the ARPES kink is one of the strongest evidence that there is strong electron-phonon coupling in HTSCs. To confirm this, [...]

Magnetic Resonance Mode and Its Relation with Thermodynamics of HTSCs

The most prominent feature of spin fluctuation in YBCO6+x system is the 41 meV resonance peak which appears below the Tc of the optimal sample. This feature (and strong spin fluctuation for all x values in this system) has been considered as an important experimental evidence for the magnetic interaction pairing of HTSCs although its [...]

Special Relationship between Real and Momentum Spaces

Scientists from the USA, China and Japan have studied the Furrier transform scanning tunneling spectroscopy (FT-STS) of Bi-2212 crystals to find the relation between the features of r-space and k-space electronic structures of HTSCs: such as the modulation of the electronic local density of states (LDOS~g(r,ω)) observed by STM, and coherence peak, Fermi surface and [...]