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arXiv · cond-mat/0607155

Correlation between oxygen isotope effects on the transition temperature and the magnetic penetration depth in high-temperature superconductors close to optimal doping

Abstract

The oxygen-isotope (^{16}O/^{18}O) effect (OIE) on the in-plane magnetic penetration depth λ_{ab}(0) in optimally-doped YBa_2Cu_3O_{7-δ} and La_{1.85}Sr_{0.15}CuO_4, and in slightly underdoped YBa_2Cu_4O_8 and Y_{0.8}Pr_{0.2}Ba_2Cu_3O_{7-δ} was studied by means of muon-spin rotation. A substantial OIE on λ_{ab}(0) with an OIE exponent β_O=-d\lnλ_{ab}(0)/d\ln M_O\approx - 0.2 (M_O is the mass of the oxygen isotope), and a small OIE on the transition temperature T_c with an OIE exponent α_O=-d\ln T_{c}/d \ln M_O\simeq0.02 to 0.1 were observed. The observation of a substantial isotope effect on λ_{ab}(0), even in cuprates where the OIE on T_c is small, indicates that lattice effects play an important role in cuprate HTS.

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R. Khasanov, A. Shengelaya, K. Conder, E. Morenzoni, I. M. Savić, J. Karpinski, H. Keller. 2006-07-06. Correlation between oxygen isotope effects on the transition temperature and the magnetic penetration depth in high-temperature superconductors close to optimal doping. https://doi.org/10.1103/physrevb.74.064504

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