Abstract
We have used high energy inelastic neutron scattering to study the magnetic fluctuation spectrum of La
2CuO
4 in the energy and momentum ranges 30⩽ħ;σ⩽140 meV and |
q|⩽0.2 Å
−1, respectively. Our results are consistent, within the experimental error, with conventional spin wave theory the low temperature spin wave velocity, being 850±30 meV Å
-1.