The magnetic correlations within the cuprates have undergone intense scrutiny as part of efforts to understand high-temperature superconductivity. We explore the evolution of the magnetic correlations along the nodal direction of the Brillouin zone in La2−xSrxCuO4, spanning the doping phase diagram from the antiferromagnetic Mott insulator at x=0 to the metallic phase at x=0.26. Magnetic excitations along this direction are found to be systematically softened and broadened with doping, at a higher rate than the excitations along the antinodal direction. This phenomenology is discussed in terms of the nature of the magnetism in the doped cuprates. Survival of the high-energy magnetic excitations, even in the overdoped regime, indicates that these excitations are marginal to pairing, while the influence of the low-energy excitations remains ambiguous.
Meyers, D., Miao, H., Walters, A., Bisogni, V., Springell, R., d'Astuto, M., Danz, M., Pelliciari, J., Huang, H., Okamoto, J., Huang, D., Hill, J., He, X., Bozovic, I., Schmitt, T., & Dean, M. (2017). Doping dependence of the magnetic excitations in La2−xSrxCuO4. Physical Review B, 95(7), . https://doi.org/10.1103/PhysRevB.95.075139