Spin pseudogap in La2-xSrxCuO4 studied by neutron scattering -: art. no. 134521

Spin excitations of La2-xSrxCuO4 have been studied using inelastic neutron scattering techniques in the energy range of 2 meV less than or equal toomegaless than or equal to12 meV and the temperature range of 8 Kless than or equal toTless than or equal to150 K. We observed a signature of a spin pseudogap in the excitation spectrum above T-c for the slightly overdoped sample with x=0.18. On heating, the spin pseudogap gradually collapses between T=80 and 150 K. For the x=0.15 and 0.20, although the visibility of gaplike structure at Tsimilar toT(c) is lower compared to the x=0.18 sample, the broad bump of chi(')(omega) appears at omega similar to5 meV, close to the spin-gap energy at base temperature, suggests the existence of the spin pseudogap in the normal state.