QUEST - QUantum matErials for Sustainable Technologies

On the origin of circular dichroism in ARPES spectra from graphene, WSe$_2$, and other quantum materials

Dec 2, 2024, 5:00 PM

30m

Sala Kastler (Adriatico Guesthouse, ICTP, Trieste, Italy)

Invited Oral Session 2

Speaker

Dr Lukasz Plucinski (PGI-6 FZ Juelich)

Description

On the example of graphene, we will discuss various contributions to circular dichroism in angle-resolved photoemission (CD-ARPES) [1,2] which include phase shifts of the participating partial waves [3], the interatomic phase shifts [4], and the CD due to elastic scattering of an excited electron [5]. Multiple scattering calculations are performed using the EDAC cluster code [6] and the KKR-based one-step model [7]. Subsequently, we perform similar analysis for WSe$_2$, a material where orbital characters are relatively well-defined.
Finally, a simple interatomic interference model that qualitatively explains asymmetric spin-polarized ARPES (spin-ARPES) spin texture from WTe$_2$ single crystal surface [4] is presented.
This study aims to explore how CD-ARPES and spin-ARPES techniques can enhance the understanding of topological materials.

[1] arXiv:2309.02187 (2023)
[2] JESRP 258, 147219 (2022)
[3] JESRP 214, 29 (2017)
[4] PRL 130, 146401 (2023)
[5] JJAP 32, L1480 (1993)
[6] PRB 63, 75404 (2001)
[7] PRB 83, 121408(R) (2011)