Pseudogap and incommensurate magnetic fluctuations in YBa_2Cu_3O_{6. 6}
arXiv:cond-mat/9712311 · doi:10.1016/S0921-4526(97)00633-9
Abstract
Unpolarized inelastic neutron scattering is used to study the temperature and wave vector dependence of the dynamical magnetic susceptibility, $Ï''(q,Ï)$, of a well characterized single crystal $YBa_2Cu_3O_{6.6}$ ($T_c=62.7$ K). We find that a pseudogap opens in the spin fluctuation spectrum at temperatures well above $T_c$. We speculate that the appearance of the low frequency incommensurate fluctuations is associated with the opening of the pseudogap. To within the error of the measurements, a gap in the spin fluctuation spectrum is found in the superconducting state.
6 pages, 3 ps figs, Proceedings of ICNS, Physica B, to be published