تقرير
Built-in Bernal gap in large-angle-twisted monolayer-bilayer graphene
| العنوان: | Built-in Bernal gap in large-angle-twisted monolayer-bilayer graphene |
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| المؤلفون: | Boschi, Alex, Gebeyehu, Zewdu M., Slizovskiy, Sergey, Mišeikis, Vaidotas, Forti, Stiven, Rossi, Antonio, Watanabe, Kenji, Taniguchi, Takashi, Beltram, Fabio, Fal'ko, Vladimir I., Coletti, Camilla, Pezzini, Sergio |
| سنة النشر: | 2024 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Mesoscale and Nanoscale Physics |
| الوصف: | Atomically thin materials offer multiple opportunities for layer-by-layer control of their electronic properties. While monolayer graphene (MLG) is a zero-gap system, Bernal-stacked bilayer graphene (BLG) acquires a finite band gap when the symmetry between the layers' potential energy is broken, usually, via a large electric field applied in double-gate devices. Here, we introduce an asymmetric twistronic stack comprising both MLG and BLG, synthesized via low-pressure chemical vapor deposition (LP-CVD) on Cu. Although a large ($\sim30^{\circ}$) twist angle decouples the MLG and BLG electronic bands near Fermi level, we find that the layer degeneracy in the BLG subsystem is lifted, producing a gap in the absence of external fields. The built-in interlayer asymmetry originates from proximity-induced energy shifts in the outermost layers and requires a displacement field of $0.14$ V/nm to be compensated. The latter corresponds to a $\sim10$ meV intrinsic BLG gap, a value confirmed by our thermal-activation measurements. The present results highlight the role of structural asymmetry and encapsulating environment, expanding the engineering toolbox for monolithically-grown graphene multilayers. Comment: 23 pages, 4 figures and supporting information |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2406.04732 |
| رقم الأكسشن: | edsarx.2406.04732 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |