X-ray Spectroscopy Special Interest Gp Seminar

Time:  10:00-11:00 am

Abstract: The understanding of the interactions leading to the intriguing properties of quantum materials requires the investigation of their elementary excitations in energy and momentum space. In this context, Resonant Inelastic X-ray Scattering (RIXS) has emerged as a powerful probe with prime sensitivity to electronic (spin, orbital, and charge) and lattice degrees of freedom. Thanks to recent developments RIXS has been employed in the investigation of many different systems, including cuprates, Fe-based superconductors, and low dimensional magnets. One of the latest interests of our group at Brookhaven National Laboratory has been the investigation of ultrathin films and materials where the properties are markedly different than the bulk.

In my talk I will present our recent RIXS investigations in the field of ultrathin films as well as technological advances that permitted these achievements. I will focus on two different scientific cases, the effect of confinement on the spin excitations of metallic iron, and the evolution of the spin fluctuations in FeSe from the bulk down to the monolayer. I will show how RIXS can identify the elementary excitations in samples as thin as a single unit cell and its advantage over other techniques such as neutron and Raman scattering. By comparison with the respective bulk materials, I will show how the limited thickness affects the spin excitations and the consequences in the description of the interactions of those systems. Finally, I will conclude by presenting a view on new perspective in the use of RIXS in ultrathin films and materials such as van der Waals, and strongly correlated electron systems.