Theory and Software Group (X-ray Science Division)

The Theory and Software Group was established in 2004 as a joint program between the Department of Physics at Northern Illinois University and the Advanced Photon Source.

The group's focus is on

• X-ray spectroscopy, including X-ray Absorption and X-ray Magnetic Dichroism, Inelastic X-ray Scattering.
• Magnetism and strongly correlated systems and the study thereof with (polarized) X-rays.
• Systems away from equilibrium
• Powder diffraction analysis (also combined with EXAFS, SAXS)
• Software development

The Group also maintain and develops a wide variety of codes to analyze and model X-ray experiments.
For more information, see the Scientific Software page.

At the APS, the Theory Group collaborates with experimental groups at several beam lines. At NIU, the theory effort is integrated with the nanoscience program of the Institute for Nanoscience, Engineering and Technology (INSET) at NIU's Department of Physics. At Argonne, the theory program is linked with the Condensed-Matter Theory Group at the Materials Science Division, led by Mike Norman.

2010 Science Highlights


Observation of phonons with resonant inelastic x-ray scattering

H. Yavas, M. van Veenendaal, J. van den Brink, L. J. P. Ament, A. Alatas, B. M. Leu, M.-O. Apostu, N. Wizent, G. Behr, W. Sturhahn, H. Sinn, and E. E. Alp
J. Phys.: Cond. Mat. 22, 485601 (2010).


Orbital magnetism and spin-orbit effects in the electronic structure of BaIrO3
M. A. Laguna-Marco, D. Haskel, N. Souza-Neto, J. C. Lang, V. V. Krishnamurthy, S. Chikara, G. Cao, and Michel van Veenendaal
Phys. Rev. Lett. 105, 216407 (2010).










Resonant inelastic x-ray scattering studies of elementary excitations
L. J. P. Ament, M. van Veenendaal, T. P. Devereaux, J. P. Hill, and J. van den Brink
Rev. Mod. Phys. 83, 705 (2011).