Momentum-resolved linear dichroism in bilayer MoS${}_2$

Abstract

Inversion-symmetric crystals are optically isotropic and thus naively not expected to show dichroism effects in optical absorption and photoemission processes. Here, we find a strong linear dichroism effect (up to 42.4%) in the conduction band of inversion-symmetric bilayer MoS${}_2$, when measuring energy- and momentum-resolved snapshots of excited electrons by time- and angle-resolved photoemission spectroscopy. We model the polarization-dependent photoemission intensity in the transiently-populated conduction band using the semiconductor Bloch equations and show that the observed dichroism emerges from intralayer single-particle effects within the isotropic part of the dispersion. This leads to optical excitations with an anisotropic momentum-dependence in an otherwise inversion symmetric material.

arXiv comment10 pages including supporting information, 3 figures in the main paper and 4 figures in the supporting information

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• Time- and Angle-Resolved Photoemission Studies of Quantum Materials
• How Circular Dichroism in time- and angle-resolved photoemission can be used to spectroscopically detect transient topological states in graphene
• Polarization-Modulated Angle-Resolved Photoemission Spectroscopy: Towards Circular Dichroism without Circular Photons and Bloch Wavefunction Reconstruction
• Exciton-Driven Renormalization of Quasiparticle Band Structure in Monolayer MoS2
• Layer and orbital interference effects in photoemission from transition metal dichalcogenides
• Berry Curvature Signatures in Chiroptical Excitonic Transitions
• Ultrafast Polarization-Tunable Monochromatic Extreme Ultraviolet Source at High-Repetition-Rate
• Probing magnetic orbitals and Berry curvature with circular dichroism in resonant inelastic X-ray scattering
• Polarization dependent photoemission as a probe of the magnetic ground state in the layered ferromagnet VI3