SPring-8, the large synchrotron radiation facility

Speaker : Dr. Lewis Andrew Wray

Language : English

Affiliate : Lawrence Berkeley National Laboratory

Title : Recent ARPES and RIXS developments at the Advanced Light Source: Topological insulator interfaces and high resolution copper M-Edge RIXS

Abstract :
I will present recent research results from collaborative projects at the Advanced Light Source, focusing on preliminary measurements at the newly constructed MERLIN RIXS beamline and ongoing ARPES explorations of the unique surface physics of topological insulators

Topological insulators are a recently discovered class of semiconductors with bulk topological order that causes a wide range of unusual surface properties, such as the appearance of a nanometer thick shell of spin-helical Dirac electronic states. Our ARPES measurements demonstrate how topological order can be induced through chemical alloying in BiTl(S_1-δSe_δ)₂, and show that when topological insulators are interfaced with normal metallic layers, they manifest novel classes of semiconductor junction behavior.

The Advanced Light Source MERLIN RIXS beamline (4.0.3) is currently under commissioning, and will soon be open to general users for resonant inelastic X-ray scattering experiments. I will discuss new scientific explorations that are expected to be possible with the system, including preliminary data obtained during the commissioning period on cuprate samples. Because very few previous studies have been performed at the M-Edge, we will devote time to discussing how M-Edge scattering data at MERLIN resemble and differ from the more broadly studied transition metal K- and L-edges, including critical parameters of the excitation process such as fitted intermediate state lifetimes, X-ray penetration depth, spin-orbit coupling and scattering intensity for different types of excitation mode.

Organizer： Kenji Ishii
Mail:kenji@spring8.or.jp
PHS:3128