EFFECTS OF ELECTRON CORRELATION ON
MAGNETIC COMPTON PROFILES OF NI IN THE GW APPROXIMATION
Yasunori Kubo
Department of Physics,
College of Humanities and Sciences, Nihon University, Tokyo 156-8550 (
kubo@chs.nihon-u.ac.jp)
The magnetic Compton profiles
(MCPÕs) are studied with the conventional band theory based on the
local-density approximation(LDA) and so-called GW approximation (GWA) connected
band theory. In the GWA, the basis sets, eigen-energies and eigen-states
generated by the full-potential linearized augmented-plane wave method(FLAPW),
are used.
Since the magnetic moment of Ni is 0.6 mB , which is
about 4 times smaller than that of Fe, it is not easy to measure MCP with good
statistical accuracy. However, recent MCPÕs [1,2] using Storage-Ring have
demonstrated discrepancies between the experiments and conventional band
calculations using LDA in lower momentum region, where the Fermi surface
structures and the hybridization between the 3d- and s,p- electrons
predominantly influence the momentum distributions of magnetic electrons. The
discrepancies are examined from the point of view of electron correlation
effects. The occupation number densities N(k)Õs are evaluated from
a first-principle calculation of the spectral function within the GWA. The
MCPÕs are calculated using the N(k)Õs.
References
1
Dixon, M.A.G., Duffy, J.A., Gardelis,
S., McCarthy, J.E., Cooper, M.J., Dugdale, S.B., Jarlborg, T., Timms, D.N.,
(1998) J. Phys.: Condens. Matter 10 2759-2771.
2
Kakutani, Y., Kubo, Y., Koizumi, A., Sakai, N., Ahuja, B.L.,
Sharma, B.K. (2003) J. Phys. Soc. Jpn. 72 in print.