This issue is to calculate the 2-magnon structure factor like in Fig 4j of this paper.
SpinW calculates the single magnon energies ω(q). Whilst in most cases only one magnon is excited at a time by e.g. neutron scattering, in principle, however, two (or more) magnons can be excited from a single scattering event.
In order to conserve energy and momentum, the following kinematic restriction applies:
In the case of non-interacting magnons, the structure factor of the two-magnon scattering can be obtained [PS - this needs checking!] by replacing the longitudinal component of the spin-spin correlation with
This issue is to calculate the 2-magnon structure factor like in Fig 4j of this paper.
SpinW calculates the single magnon energies ω(q). Whilst in most cases only one magnon is excited at a time by e.g. neutron scattering, in principle, however, two (or more) magnons can be excited from a single scattering event.
In order to conserve energy and momentum, the following kinematic restriction applies:
In the case of non-interacting magnons, the structure factor of the two-magnon scattering can be obtained [PS - this needs checking!] by replacing the longitudinal component of the spin-spin correlation
with