MAGNETIC DYNAMICS OF SUPERCONDUCTING LA1.86SR0.14CUO4

The general magnetic response function chi(Q, omega) of a superconducting (T(c) = 33 K) single crystal of La1.86Sr0.14CuO4 is measured using inelastic neutron scattering. There is no gap in the magnetic fluctuation spectrum of the normal state. Superconductivity reduces chi"(Q, omega) in progressively greater proportion as HBAR-omega decreases below 6 meV. The superconducting transition coincides with a sharp maximum in the temperature-dependent chi"(Q, omega) for HBAR-omega = 4 meV and Q fixed at the incommensurate wave vector characterizing the magnetic fluctuations in the normal state.