In condensed matter physics, the dynamic structure factor (or dynamical structure factor) is a mathematical function that contains information about inter-particle correlations and their time evolution. It is a generalization of the structure factor that considers correlations in both space and time. Experimentally, it can be accessed most directly by inelastic neutron scattering or X-ray Raman scattering.

). It is defined as:

, is called the intermediate scattering function and can be measured by neutron spin echo spectroscopy. The intermediate scattering function is the spatial Fourier transform of the van Hove function:

Thus we see that the dynamical structure factor is the spatial and temporal Fourier transform of van Hove:

The dynamic structure is exactly what is probed in coherent inelastic neutron scattering. The differential cross section is :

is the scattering length.

The van Hove function

point particles is defined as:

It can be rewritten as:

References

Further reading

• Lovesey, Stephen W. (1986). Theory of Neutron Scattering from Condensed Matter - Volume I: Nuclear Scattering. Oxford University Press. .