This method was always considered a competitive method to positron
annihilation (PA) where the "test particles" injected into the probe are
high-energetic x or gamma photons. The experimental investigation of
these photons scattered by the electrons of the sample leads to
so-called Compton profiles which can be considered one-dimensional
projections of the electron momentum density (EMD). Obviously, the
greatest advantage of CS compared to PA is the fact that since no
go in or out of the sample, the results of this method are not
complicated by "enhancement effects" as mentioned before. On the other
hand, for a long time, the usefulness of CS has been strongly limited by
a lack of adequate momentum resolution (typically 0.4-0.5 a.u. in
comparison with 0.07 a.u. for the PA spectroscopy).
However, since about 1985, the availibility of high energy, high
intensity sychrotron sources decisively improved the momentum resolution
of CS and made this method a realistic alternative to PA both for Fermi
surface and EMD studies. These new "high-resolution Compton experiments"
yield high-quality Compton profiles including a plenty of details and
led to a real "boom" of corresponding theoretical investigations.
Similar to positron annihilation, Compton scattering is very
attractive to theorists because of the fact that almost all
methods of theoretical solid state physics are to be used for a proper
description of Compton profiles (Green's functions and Feynman diagrams,
static and dynamical dielectric matrices, self-energy and GW methods
etc.), demanding high-level work from the physical, mathematical and
computational point of view.
Back to Heinz Sormann
After intensive preparations during the recent year 2001, I plan to
enter the Compton scattering field in the immediate future.