Possible isotope effect on the resonance peak formation in high-Tc cuprates

عدم تقارن الکترون-حفره در کوپراتهای دمای بالا از دید نظری

  Asymmetric features of various physical quantities in the normal and superconducting states between hole- and electron-doped cuprate high-temperature superconductors have been an issue of debate for a long time. Their exploration is very important for the understanding not only of the mechanism of high-Tc superconductivity but also of the nature of doped-Mott insulators. Presented in this rev...

From Magnons to the Resonance Peak: Spin Dynamics in High-tc Superconducting Cuprates by Inelastic Neutron Scattering

Evidence for the presence of the magnetically-mediated superconductivity in hole-doped cuprates

The phase diagram of hole-doped cuprates is discussed. By examining carefully some recent inelastic neutron scattering data obtained on hole-doped cuprates and on a heavy fermion compound UPd2Al3 in which the superconductivity is mediated by spin fluctuations, we conclude that the coherent gap in hole-doped cuprates has most likely the magnetic origin and scales with Tc, on average, as 2∆c/kBTc...

0 Large oxygen - isotope effect in Sr 0 . 4 K 0 . 6 BiO 3 : Evidence for phonon - mediated superconductivity

Oxygen-isotope effect has been investigated in a recently discovered superconductor Sr0.4K0.6BiO3. This compound has a distorted perovskite structure and becomes superconducting at about 12 K. Upon replacing 16O with 18O by 60-80%, the Tc of the sample is shifted down by 0.32-0.50 K, corresponding to an isotope exponent of αO = 0.40(5). This isotope exponent is very close to that for a similar ...

Oxygen Isotope Effects on Tc Related to Polaronic Superconductivity in Underdoped Cuprates

The planar oxygen isotope effect on Tc observed in copper oxide superconductors is remarkable in that it increases from near nil at optimal doping to a value twice that derived from BCS theory in the underdoped region. This behavior is quantitatively followed by a formula proposed by Kresin and Wolf in 1994 for polarons along the c-axis. Herein it is revisited in a more transparent way, and it ...