Broken mirror symmetry in excitonic response of reconstructed domains in twisted MoSe$_2$/MoSe$_2$ bilayers

التفاصيل البيبلوغرافية
العنوان: Broken mirror symmetry in excitonic response of reconstructed domains in twisted MoSe$_2$/MoSe$_2$ bilayers
المؤلفون: Sung, Jiho, Zhou, You, Scuri, Giovanni, Zólyomi, Viktor, Andersen, Trond I., Yoo, Hyobin, Wild, Dominik S., Joe, Andrew Y., Gelly, Ryan J., Heo, Hoseok, Bérubé, Damien, Valdivia, Andrés M. Mier, Taniguchi, Takashi, Watanabe, Kenji, Lukin, Mikhail D., Kim, Philip, Fal'ko, Vladimir I., Park, Hongkun
المصدر: Nature Nanotechnology 2020
سنة النشر: 2020
المجموعة: Condensed Matter
Physics (Other)
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science, Physics - Optics
الوصف: Structural engineering of van der Waals heterostructures via stacking and twisting has recently been used to create moir\'e superlattices, enabling the realization of new optical and electronic properties in solid-state systems. In particular, moir\'e lattices in twisted bilayers of transition metal dichalcogenides (TMDs) have been shown to lead to exciton trapping, host Mott insulating and superconducting states, and act as unique Hubbard systems whose correlated electronic states can be detected and manipulated optically. Structurally, these twisted heterostructures also feature atomic reconstruction and domain formation. Unfortunately, due to the nanoscale sizes (~10 nm) of typical moir\'e domains, the effects of atomic reconstruction on the electronic and excitonic properties of these heterostructures could not be investigated systematically and have often been ignored. Here, we use near-0$^o$ twist angle MoSe$_2$/MoSe$_2$ bilayers with large rhombohedral AB/BA domains to directly probe excitonic properties of individual domains with far-field optics. We show that this system features broken mirror/inversion symmetry, with the AB and BA domains supporting interlayer excitons with out-of-plane (z) electric dipole moments in opposite directions. The dipole orientation of ground-state $\Gamma$-K interlayer excitons (X$_{I,1}$) can be flipped with electric fields, while higher-energy K-K interlayer excitons (X$_{I,2}$) undergo field-asymmetric hybridization with intralayer K-K excitons (X$_0$). Our study reveals the profound impacts of crystal symmetry on TMD excitons and points to new avenues for realizing topologically nontrivial systems, exotic metasurfaces, collective excitonic phases, and quantum emitter arrays via domain-pattern engineering.
Comment: 29 pages, 4 figures in main text, 6 figures in supplementary information
نوع الوثيقة: Working Paper
DOI: 10.1038/s41565-020-0728-z
URL الوصول: http://arxiv.org/abs/2001.01157
رقم الأكسشن: edsarx.2001.01157
قاعدة البيانات: arXiv
الوصف
DOI:10.1038/s41565-020-0728-z