ELECTRONIC RAMAN-SCATTERING OF TL-2223 AND THE SYMMETRY OF THE SUPERCONDUCTING GAP

Single crystalline Tl2Ba2Ca2Cu3O10 was studied using electronic Raman scattering. The renormalization of the scattering continuum was investigated as a function of the scattering geometry to determine the superconducting energy gap 2 Delta((k) over cap). The A(1g) and B-2g-symmetry component show a linear frequency behavior of the scattering intensity with a peak related to the energy gap, while the B-1g-symmetry component shows a characteristic behaviour at higher frequencies. The observed frequency dependencies are consistent with a d(x)2-(y)2-wave symmetry of the gap and yield a ratio of 2 Delta(0)/k(B)T(c)=7.4. With the polarization of the scattered and incident light either parallel or perpendicular to the CuO2-planes a strong anisotropy due to the layered structure was detected, which indicates an almost 2 dimensional behavior of this system.