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.

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

References in corpus (6)

• Valley polarization in MoS2 monolayers by optical pumping
• The Valley Hall Effect in MoS2 Transistors
• Electronic Structure of Epitaxial Single-Layer MoS${}_2$
• Spin and Valley Control of Free Carriers in Single-Layer WS${}_2$
• Contact-Induced Semiconductor-to-Metal Transition in Single-Layer WS${}_2$
• Layer and orbital interference effects in photoemission from transition metal dichalcogenides

Cited by in corpus (1)

• Layer and orbital interference effects in photoemission from transition metal dichalcogenides