Intervalley Scattering of Interlayer Excitons in a MoS2/MoSe2/MoS2 Heterostructure in High Magnetic Field

• DOI: 10.1021/acs.nanolett.8b01484
• Publication Date: 2018-05-23T20:48:04Z
• Authors: Alessandro Surrente; Łukasz Kłopotowski; Nan Zhang; Michal Baranowski; Anatolie A. Mitioglu; Mariana V. Ballottin; Peter C.M. Christ...; Dumitru Dumcenco; Yen-Cheng Kung; Duncan K. Maude; Andras Kis; Paulina Plochocka
• Keywords: [PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con]; Transition metal dichalcogenides, van der Waals heterostructures, interlayer exciton, magnetophotoluminescence, valley polarization; Soft Condensed Matter and Nanomaterials; Condensed Matter - Mesoscale and Nanoscale Physics; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); 0103 physical sciences; FOS: Physical sciences; 530; 01 natural sciences

Degenerate extrema in the energy dispersion of charge carriers in solids, also referred to as valleys, can be regarded as a binary quantum degree of freedom, which can potentially be used to implement valleytronic concepts in van der Waals heterostructures based on transition metal dichalcogenides. Using magneto-photoluminescence spectroscopy, we achieve a deeper insight into the valley polarization and depolarization mechanisms of interlayer excitons formed across a MoS$_2$/MoSe$_2$/MoS$_2$ heterostructure. We account for the non-trivial behavior of the valley polarization as a function of the magnetic field by considering the interplay between exchange interaction and phonon mediated intervalley scattering in a system consisting of Zeeman-split energy levels. Our results represent a crucial step towards the understanding of the properties of interlayer excitons, with strong implications for the implementation of atomically thin valleytronic devices.<br/>just accepted in Nano Letters, DOI: 10.1021/acs.nanolett.8b01484<br/>