Kagom\'e quantum oscillations in graphene superlattices

التفاصيل البيبلوغرافية
العنوان: Kagom\'e quantum oscillations in graphene superlattices
المؤلفون: de Vries, Folkert K., Slizovskiy, Sergey, Tomić, Petar, Kumar, Roshan Krishna, Garcia-Ruiz, Aitor, Zheng, Giulia, Portolés, Elías, Ponomarenko, Leonid A., Geim, Andre K., Watanabe, Kenji, Taniguchi, Takashi, Fal'ko, Vladimir, Ensslin, Klaus, Ihn, Thomas, Rickhaus, Peter
المصدر: Nano Lett. 2024, 24, 2, 601
سنة النشر: 2023
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
الوصف: Periodic systems feature the Hofstadter butterfly spectrum produced by Brown--Zak minibands of electrons formed when magnetic field flux through the lattice unit cell is commensurate with flux quantum and manifested by magneto-transport oscillations. Quantum oscillations, such as Shubnikov -- de Haas effect and Aharonov--Bohm effect, are also characteristic for electronic systems with closed orbits in real space and reciprocal space. Here we show the intricate relation between these two phenomena by tracing quantum magneto-oscillations to Lifshitz transitions in graphene superlattices, where they persist even at relatively low fields and very much above liquid-helium temperatures. The oscillations originate from Aharonov--Bohm interference on cyclotron trajectories that form a kagom\'e-shaped network characteristic for Lifshitz transitions. In contrast to Shubnikov - de Haas oscillations, the kagom\'e oscillations are robust against thermal smearing and they can be detected even when the Hofstadter butterfly spectrum is undermined by electron's scattering. We expect that kagom\'e quantum oscillations are generic to rotationally-symmetric two-dimensional crystals close to Lifshitz transitions.
Comment: 7+7 pages
نوع الوثيقة: Working Paper
DOI: 10.1021/acs.nanolett.3c03524
URL الوصول: http://arxiv.org/abs/2303.06403
رقم الأكسشن: edsarx.2303.06403
قاعدة البيانات: arXiv
الوصف
DOI:10.1021/acs.nanolett.3c03524