un 2 00 3 Anomalous oxygen isotope effect on the in - plane FIR conductivity of detwinned YBa

Charged magnons and magneto-elastic polarons in the mid-infrared spectrum of YBa

The optical conductivity of undoped and low-doped YBa Cu O is studied in detail in the mid-infrared range. Full 2 3 6 16 18 Ž . Ž . isotope substitution of O with O is used to a study the optical phonons in the far-infrared and b identify the rich structure emerging in the mid-infrared from multiphonon and bimagnon-plus-phonon absorption. Substitution of Zn in the CuO planes allows direct obser...

v 2 [ co nd - m at . s up r - co n ] 1 6 Se p 20 02 Oxygen Phonon Branches in Detwinned YBa

Effect of Ni impurities on the optical properties of YBa2Cu3O61y

The optical properties of twinned single crystals of YBa2(Cu12xNix)3O61y have been determined for a nominally pure system and for Ni concentrations of x50.0075 and 0.014 with oxygen dopings of y50.60 ~underdoped! and 0.95 ~optimal! over a wide frequency range above and below Tc . The optical conductivity of the twinned materials shows a rapid increase in the residual conductivity at low frequen...

Effect of Variable Thermal Conductivity and the Inclined Magnetic Field on MHD Plane Poiseuille Flow in a Porous Channel with Non-Uniform Plate Temperature

The aim of this paper is to investigate the effect of the variable thermal conductivity and the inclined uniform magnetic field on the plane Poiseuille flow of viscous incompressible electrically conducting fluid between two porous plates Joule heating in the presence of a constant pressure gradient through non-uniform plate temperature. It is assumed that the fluid injection occurs at lower pl...

Determination of the condensate from optical techniques in unconventional superconductors

The optical properties of superconductors, in particular the real parts of the conductivity and the dielectric function, may be used to calculate the strength of the condensate. In systems where all the free carriers collapse into the condensate, this approach works well. However, in gapless systems, and in unconventional systems in which the superconducting energy gap is observed to have zeros...