Using high-resolution magnetometry we have investigated in detail the magnetization M above the critical temperature Tc in Bi 2Sr2CaCu2O8. In a broad range of temperature T above; Tc, we find that M(T, H) is strongly non-linear in the field H. We show that as T → Tc the susceptibility Χ(T, H) diverges to very large values (Χ → -1) if measured in weak H. In addition, M(H) displays an anomalous non-analytic form M ∼ H 1/δ in weak fields with a strongly T-dependent exponent δ(T). These features strongly support the proposal that, above T c, the pair condensate survives to support significant London rigidity.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)