Dynamic structure factor

In condensed matter physics, the dynamic structure factor is a mathematical function that contains information about inter-particle correlations and their time evolution. Experimentally, it can be accessed most directly by inelastic neutron scattering.

The dynamic structure factor is most often denoted S(q,ω), where q (also k) is a wave vector (a wave number for isotropic materials), and ω a frequency (sometimes stated as energy, $\hbar\omega$). It is the spatial and temporal Fourier transform of van Hove's time-dependent pair correlation function G(r,t), whose Fourier transform with respect to r, F(Q,t), is called the intermediate scattering function and can be measured by neutron spin echo spectroscopy.^[1] In an isotropic sample (with scalar r), G(r,t) is a time dependent radial distribution function.

References

1. ^ Hansen, J.P.; McDonald, I.R. (1986). Theory of Simple Liquids. Academic Press. 

Further reading

• van Hove, L. (1954). "Correlations in Space and Time and Born Approximation Scattering in Systems of Interacting Particles". Physical Review 95 (1): 249. Bibcode 1954PhRv...95..249V. doi:10.1103/PhysRev.95.249.