Scattering makes a difference in circular dichroic angle-resolved photoemission

Abstract

Recent years have witnessed a steady progress towards blending 2D quantum materials into technology, with future applications often rooted in the electronic structure. Since crossings and inversions of electronic bands with different orbital characters determine intrinsic quantum transport properties, knowledge of the orbital character is essential. Here, we benchmark angle-resolved photoelectron emission spectroscopy (ARPES) as a tool to experimentally derive orbital characters. For this purpose we study the valence electronic structure of two technologically relevant quantum materials, graphene and WSe${}_2$, and focus on circular dichroism that is believed to provide sensitivity to the orbital angular momentum. We analyze the contributions related to angular atomic photoionization profiles, interatomic interference, and multiple scattering. Regimes in which initial-state properties could be disentangled from the ARPES maps are critically discussed and the potential of using circular-dichroic ARPES as a tool to investigate the spin polarization of initial bands is explored. For the purpose of generalization, results from two additional materials, GdMn${}_6$Sn${}_6$ and PtTe${}_2$ are presented in addition. This research demonstrates rich complexity of the underlying physics of circular-dichroic ARPES, providing new insights that will shape the interpretation of both past and future circular-dichroic ARPES studies.

12 pages, 7 figures

References in corpus (8)

• Orbitronics: Orbital Currents in Solids
• Time-domain observation of ballistic orbital-angular-momentum currents with giant relaxation length in tungsten
• Measurements of the quantum geometric tensor in solids
• Dyakonov-Perel-like Orbital and Spin Relaxations in Centrosymmetric Systems
• Signatures of a surface spin-orbital chiral metal
• Ultrafast Dynamics of Orbital Angular Momentum of Electrons Induced by Femtosecond Laser Pulses: Generation and Transfer Across Interfaces
• Geometry-induced spin-filtering in photoemission maps from WTe${}_2$ surface states
• Light-induced torque in ferromagnetic metals via orbital angular momentum generated by photon-helicity