Comment on ‘‘Electronic Raman scattering in high-Tcsuperconductors: A probe ofd

Matthias C. Krantz

¹

,

M. Cardona

²

Superconductivity-induced resonant Raman scattering in multilayer high-Tcsuperconductors

“…Therefore, "in resonance" , the relative positions of the pair breaking peaks in the A 1g , B 1g , and B 2g channels is 2∆(A1g) = 2∆(B1g) > 2∆(B2g), as predicted theoretically for a d-wave multi-layer superconductor [9,11,12] but not observed to date. This implies that the resonant part of the A 1g scattering is primarily free from screening effect due t o the long range Coulomb force [12] and/or collective spin fluctuation [17].…”

“…Krantz and Cardona have pointed out that this screening effect scenario is valid only in single CuO2-layer HTSC, or in the case of completely degenerated bands for the layers [9]. If the bands are non-degenerated, the A 1g channel includes the interband Raman process, in addition to the intraband one.…”

Electronic Raman scattering in the single-CuO2layered superconductorTl2Gasparov1, Lemmens2, Brinkmann3 et al. 1997Phys. Rev. B301182View full textAdd to dashboardCite

“…30 our experiments show that the one-CuO 2 -plane compound Tl-2201 shows very similar behavior compared to compounds with several CuO 2 -planes, such as Tl-2223, Bi-2212 and YBaCuO [18][19][20][21][22][23][24][25][26][27]29,30 . We also found that the frequency of the B 1g maximum scales with T c , and it corresponds to the value 2∆ max /k B T c = 7.6 ± 0.4.…”

“…Recently the model calculations of Devereaux et al were criticized by Krantz and Cardona 29,30 . The main argument against this theoretical model is that the realistic electronic band structure of the crystal is important, but that the one-sheeted Fermi surface approximation used by Devereaux et al systems.…”

“…Instead, a monotonic decrease toward zero frequency is found. Moreover, for different symmetry components (A 1g , B 1g and B 2g ) the renormalization of the scattering intensity for T<T c is different and they exhibit peaks at different frequencies [18][19][20][21][22][23][24][25][26][27]29,30 . These facts have been explained by Devereaux et al 26,27 in terms of d x 2 −y 2 -wave pairing.…”