Incommensurate magnetic fluctuations in ${\mathrm{La}}_{2\mathrm{-}\mathit{x}}$${\mathrm{Sr}}_{\mathit{x}}$${\mathrm{CuO}}_4$

We use inelastic neutron scattering to establish the modulation vectors δ and correlation lengths for the incommensurate magnetic fluctuations in metallic samples of ${\mathrm{La}}_{2\mathrm{-}\mathit{x}}$ ${\mathrm{Sr}}_{\mathit{x}}$ ${\mathrm{CuO}}_4$ with x=0.075 and 0.14. In notation appropriate for a square lattice where the magnetic instability in the undoped case occurs at (π,π), the vectors δ are along (π,0) and (0,π). The correlation length ξ is larger than the distance between carriers, is weakly dependent on x, and changes significantly between 12 and 100 K for both compositions.