Birefringence and polarization rotation in resonant x-ray diffraction

Yves Joly (1) , S. P. Collins (2) , Stéphane Grenier (3) , Hélio Tolentino (4) , Maurizio de Santis (1)

1 NEEL - SIN - Surfaces, Interfaces et Nanostructures
2 DIAMOND Light source
3 NEEL - MRS - Matériaux, Rayonnements, Structure
4 NEEL - CRG - CRG & Grands instruments

Birefringence can contribute to x-ray resonant Bragg diffraction and likely explains recent novel data collected on CuO. We prove these statements using ab initio simulations which reproduce the experimental polarization effects quantitatively. We show that an unrotated polarization signal--ruled out in resonant magnetic scattering within the electric dipole approximation--arises from the dynamic change in polarization inside the material.We are able to reproduce all the related behavior with circular polarization and its dependence on the angle of rotation about the Bragg wave vector. We provide a tool to disentangle the various physical origins of the polarization rotation, providing a more complete understanding of the illuminated material.

Mots clés: CuO; Birefringence; RXD

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Yves Joly, S. P. Collins, Stéphane Grenier, Hélio Tolentino, Maurizio de Santis. Birefringence and polarization rotation in resonant x-ray diffraction. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2012, 86, pp.220101(R). ⟨10.1103/PhysRevB.86.220101⟩. ⟨hal-00843869⟩