Opportunities for studying electron correlations using a two-colour beamline at Diamond Light Source
Dr. Tien-Lin Lee (Diamond Light Source Ltd., Harwell Science and Innovation Campus, Oxfordshire, UK)

Diamond Light Sources I09 beamline is the first in the world designed to deliver both hard and soft X-rays with optimised, independent sources and optics. With the extended energy range, we offer a number of X-ray techniques that are based primarily on X-ray photoelectron and absorption spectroscopies, which can be combined to study the same spot on a sample and thus to maximise the information one can extract from a visit to the beamline. For photoelectron spectroscopy this energy range corresponds to an information depth from 0.5 to more than 20 nm, providing the bulk as well as surface sensitivity for depth-profiling of heterostructures and buried interfaces. For probing momentum dependence of electronic structures, higher excitation energies allow ARPES in addition to study 3-dimensional electronic systems and to be performed under resonance to gain chemical sensitivity. Following an introduction of the beamline, two science cases will be discussed to highlight its applications in studies of electron correlations in oxides: (1) Thickness and band-filling controlled Mott transition in epitaxial thin films of early transition metal oxides and (2) charge and spin correlations in a coupled metal-Mott insulator system: PdCrO2.