Diamond Light Source

Abstract：

Synchrotron light enables precise generation, control, and analysis of photon polarization across a wide energy range [1-3]. This capability selectively enhances elements of the light-matter cross-section, benefiting diverse synchrotron techniques probing materials at various scales. While dominant X-ray diffraction terms preserve photon polarization, resonant conditions or advanced scattering models reveal systematic polarization modification of diffracted photons. Analyzing this final polarization distinguishes scattering processes and accesses distinct system properties [4]. Consequently, X-ray polarization analysis investigates magnetic/chiral order [5,6], and, combined with synchrotron spatial resolution, maps domains [7,8]. This approach extends to excitations involving energy/momentum transfer [9]. Similarly, polarized-light-excited photoelectrons probe nanoscale topological magnetic textures and domains in quantum materials [8], complementing diffraction resolution. In this talk, I will introduce polarized light for investigating chirality and non-collinear magnetic order, discussing its key opportunities.

Reference:

[1] Malgrange, C. (1996). X-Ray Polarization and Applications. In: Authier, A., Lagomarsino, S., Tanner, B.K. (eds) X-Ray and Neutron Dynamical Diffraction. NATO ASI Series, vol 357. Springer, Boston, MA.

[2] C. Giles et al, J. Appl. Cryst. (1994). 27, 232-240.

[3] Detlefs, C et al Eur. Phys. J. Spec. Top. 208, 359–371 (2012)

[4] X-ray Scattering and Absorption by Magnetic Materials - S. W. Lovesey and S. P. Collins -Clarendon Press Oxford Series on Synchrotron Radiation (1996)

[5] N. Qureshi et al Phys. Rev. B 102, 054417 (2020)

[6] A. M. Vibhakar et al Phys. Rev. B 108, L100404 (2023)

[7] R. D. Johnson et al, Phys. Rev. Lett. 110, 217206 (2013)

[8] N. Waterfield Price et al., Phys. Rev. Lett. 117, 177601 (2016)

[9] Ueda et al, Nature 618, 946 (2023)

Brief CV of Prof. Alessandro Bombardi:

Alessandro Bombardi is the principal beamline scientist at the I16 Material and magnetism at Diamond, the first operational beamline at Diamond that he contributed to build. Prior to this position, Alessandro was Senior Beamline Scientist, Diamond Research Fellow and visiting lecturer at Oxford University. Alessandro started his scientific career with a PhD on actinides with Prof. Gerry Lander, and since he developed a fascination for strongly correlated electron systems, quantum, and multifunctional materials that he investigates mainly using x-ray and neutron-based techniques.

报告地点：M楼249会议室

主持人：刘笑然 特聘研究员

联系人：傅琦 （82649469）