ab -plane optical properties of Tl 2 Ba 2 <mml:…
1995; American Physical Society; Volume: 51; Issue: 5 Linguagem: Inglês
10.1103/physrevb.51.3312
ISSN1095-3795
AutoresA. V. Puchkov, T. Timusk, Spencer Doyle, A. M. Hermann,
Tópico(s)Superconductivity in MgB2 and Alloys
ResumoWe report on absolute ab-plane reflectivity measurements of the single-layer high-${\mathit{T}}_{\mathit{c}}$ superconductor ${\mathrm{Tl}}_{2}$${\mathrm{Ba}}_{2}$${\mathrm{CuO}}_{6+\mathrm{\ensuremath{\delta}}}$ in both the normal and superconducting states. The reflectivity has been measured from 40 to 40000 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ and the optical conductivity has been calculated from Kramers-Kronig analysis. The unusual form of the low-frequency reflectivity leads to an intense low-frequency feature in the optical conductivity. In the superconducting state, the spectral weight is strongly suppressed at frequencies below \ensuremath{\sim}800 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ due to the formation of a superfluid fraction. The value of the London penetration depth has been estimated to be 2400\ifmmode\pm\else\textpm\fi{}200 \AA{}, larger than that from muon-spin-resonance (\ensuremath{\mu}SR) experiments.
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