Direct Observation of the Oxygen Isotope Effect on the In-Plane Magnetic Field Penetration Depth in Optimally DopedYBa2Cu3O7−δ

R. Khasanov, D. G. Eshchenko, H. Luetkens, E. Morenzoni, T. Prokscha, A. Suter, N. Garifianov, M. Mali, J. Roos, K. Conder, H. Keller
2004 Physical Review Letters  
We report the first direct observation of the oxygen-isotope (^16O/^18O) effect on the in-plane penetration depth λ_ab in a nearly optimally doped YBa_2Cu_3O_7-δ film using the novel low-energy muon-spin rotation technique. Spin polarized low energy muons are implanted in the film at a known depth z beneath the surface and precess in the local magnetic field B(z). This feature allows us to measure directly the profile B(z) of the magnetic field inside the superconducting film in the Meissner
more » ... te and to make a model independent determination of λ_ab. A substantial isotope shift Δλ_ab/λ_ab=2.8(7) observed, implying that the in-plane effective supercarrier mass m_ab^∗ is oxygen-isotope dependent with Δ m_ab^∗/m_ab^∗ = 5.5(1.4)
doi:10.1103/physrevlett.92.057602 pmid:14995343 fatcat:atpaymfizzeslbyrk4wpgb7rjq