Abstract
In- and out-of-plane optical spectra and specific heat measurements for the single layer cuprate superconductor Hg Ba2 Cu O4+δ (Hg-1201) at optimal doping (Tc =97 K) are presented. Both the in-plane and out-of-plane superfluid density agree well with a recently proposed scaling relation ρs σdc Tc. It is shown that there is a superconductivity induced increase of the in-plane low frequency spectral weight which follows the trend found in underdoped and optimally doped Bi2 Sr2 Ca Cu2 O8+δ (Bi-2212) and optimally doped Bi2 Sr2 Ca2 Cu3 O10+δ (Bi-2223). We observe an increase of optical spectral weight which corresponds to a change in kinetic energy ΔW≈0.5 meV Cu which is more than enough to explain the condensation energy. The specific heat anomaly is 10 times smaller than in Y Ba2 Cu3 O6+δ (YBCO) and 3 times smaller than in Bi-2212. The shape of the anomaly is similar to the one observed in YBCO showing that the superconducting transition is governed by thermal fluctuations.
Original language | English (US) |
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Article number | 054522 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 75 |
Issue number | 5 |
DOIs | |
State | Published - Feb 26 2007 |
Externally published | Yes |