Deterministic fabrication of graphene hexagonal boron nitride moir\'e superlattices

التفاصيل البيبلوغرافية
العنوان: Deterministic fabrication of graphene hexagonal boron nitride moir\'e superlattices
المؤلفون: Kamat, Rupini V., Sharpe, Aaron L., Pendharkar, Mihir, Hu, Jenny, Tran, Steven J., Zaborski Jr., Gregory, Hocking, Marisa, Finney, Joe, Watanabe, Kenji, Taniguchi, Takashi, Kastner, Marc A., Mannix, Andrew J., Heinz, Tony, Goldhaber-Gordon, David
سنة النشر: 2024
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics
الوصف: The electronic properties of moir\'e heterostructures depend sensitively on the relative orientation between layers of the stack. For example, near-magic-angle twisted bilayer graphene (TBG) commonly shows superconductivity, yet a TBG sample with one of the graphene layers rotationally aligned to a hexagonal Boron Nitride (hBN) cladding layer provided the first experimental observation of orbital ferromagnetism. To create samples with aligned graphene/hBN, researchers often align edges of exfoliated flakes that appear straight in optical micrographs. However, graphene or hBN can cleave along either zig-zag or armchair lattice directions, introducing a 30 degree ambiguity in the relative orientation of two flakes. By characterizing the crystal lattice orientation of exfoliated flakes prior to stacking using Raman and second-harmonic generation for graphene and hBN, respectively, we unambiguously align monolayer graphene to hBN at a near-0 degree, not 30 degree, relative twist angle. We confirm this alignment by torsional force microscopy (TFM) of the graphene/hBN moir\'e on an open-face stack, and then by cryogenic transport measurements, after full encapsulation with a second, non-aligned hBN layer. This work demonstrates a key step toward systematically exploring the effects of the relative twist angle between dissimilar materials within moir\'e heterostructures.
Comment: 40 pages, 15 figures
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2405.18588
رقم الأكسشن: edsarx.2405.18588
قاعدة البيانات: arXiv