Department of Natural Sciences, Lebanese American University

Photoemission Spectroscopy (PES) is a powerful technique in directly probing the electronic structure of solids especially in its angle-resolved mode (ARPES). For this purpose, synchrotron radiation as well as high-resolution lasers and other light sources have been used.

In this talk, I will present how we have been implementing this technique to uncover various aspects of the electronic structure of quantum materials, in particular the iron-pnictide high-Tc superconductors from the early stage since their discovery in Japan in 2008.

The discussion will include the core energy levels, the three-dimensional electronic structure, the Fermi surfaces and superconducting gaps, the coupling to bosonic modes, etc.

I will also present our recent work on alpha-Sn which has recently gained much attention due to the diverse tunable topological phases it can reveal ranging from a topological insulator (TI) to a topological Dirac semimetal (TDS) depending on the applied strain in addition to its simple elemental structure, non-toxic nature and great potential for applications.

Finally, I will make a brief overview on the recent research projects we have launched at LAU.