Disentangling multipole resonances through a full x-ray polarization analysis

C. Mazzoli (1) , S. B. Wilkins (1) , Sergio Di Matteo (2, 3) , B. Detlefs (1) , C. Detlefs (1) , V. Scagnoli (1) , L. Paolasini (1) , P. Ghigna (4)

1 ESRF - European Synchrotron Radiation Facility
2 PALMS - Physique des atomes, lasers, molécules et surfaces
3 LNF - Laboratori Nazionali di Frascati = National Laboratory of Frascati
4 Dipartimento di Chimica Fisica M. Rolla

Complete polarization analysis applied to resonant x-ray scattering at the Cr K edge in K2CrO4 shows that incident linearly polarized x rays can be converted into circularly polarized x rays by diffraction at the Cr pre-edge (E=5994eV) . The physical mechanism behind this phenomenon is a subtle interference effect between purely dipole (E1-E1) and purely quadrupole (E2-E2) transitions, leading to a phase shift between the respective scattering amplitudes. This effect may be exploited to disentangle two close-lying resonances that appear as a single peak in a conventional energy scan, in this way allowing one to single out and identify the different multipole order parameters involved.

Mots clés: X-ray scattering; Theory models and numerical simulation; Optical activity

Domaines: Autre [cond-mat.other]

C. Mazzoli, S. B. Wilkins, Sergio Di Matteo, B. Detlefs, C. Detlefs, et al.. Disentangling multipole resonances through a full x-ray polarization analysis. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2007, 76, pp.195118. ⟨10.1103/PHYSREVB.76.195118⟩. ⟨hal-00905431⟩