Nano-photocurrent mapping of local electronic structure in twisted bilayer graphene

التفاصيل البيبلوغرافية
العنوان: Nano-photocurrent mapping of local electronic structure in twisted bilayer graphene
المؤلفون: Sunku, Sai S., McLeod, Alexander S., Stauber, Tobias, Yoo, Hyobin, Halbertal, Dorri, Ni, Guangxin, Sternbach, Aaron, Jiang, Bor-Yuan, Taniguchi, Takashi, Watanabe, Kenji, Kim, Philip, Fogler, Michael M., Basov, D. N.
المصدر: Nano Letters 20, 2958-2964 (2020)
سنة النشر: 2020
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics
الوصف: We report a combined nano-photocurrent and infrared nanoscopy study of twisted bilayer graphene (TBG) enabling access to the local electronic phenomena at length scales as short as 20 nm. We show that the photocurrent changes sign at carrier densities tracking the local superlattice density of states of TBG. We use this property to identify domains of varying local twist angle by local photo-thermoelectric effect. Consistent with the photocurrent study, infrared nano-imaging experiments reveal optical conductivity features dominated by twist-angle dependent interband transitions. Our results provide a fast and robust method for mapping the electronic structure of TBG and suggest that similar methods can be broadly applied to probe electronic inhomogeneities of moir\'e superlattices in other van der Waals heterostructures.
نوع الوثيقة: Working Paper
DOI: 10.1021/acs.nanolett.9b04637
URL الوصول: http://arxiv.org/abs/2006.07431
رقم الانضمام: edsarx.2006.07431
قاعدة البيانات: arXiv
الوصف
DOI:10.1021/acs.nanolett.9b04637