The electronic spin susceptibility of YBa_2Cu_3O_{ 6.95} has been measured with high precision up to 24 Tesla with 17O nuclear magnetic resonance. Its temperature dependence can be accounted for by superconducting fluctuations that result in a smooth crossover from the normal to the vortex liquid state. A magnetic field-temperature phase diagram for this crossover has been established having strong upward curvature.
Categories: cond-mat.supr-con