Localization to delocalization probed by magnetotransport of hbn/graphene/hbn stacks in the ultra-clean regime

• Main Authors: Iwasaki, T., Moriyama, M., Ahmad, N., Komatsu, K., Watanabe, K., Taniguchi, T., Wakayama, Y., Hashim, A. M., Morita, Y., Nakaharai, S.
• Format: Article
• Published: Nature Research 2021
• Subjects: T Technology (General)
• Online Access: http://eprints.utm.my/id/eprint/95617/; http://dx.doi.org/10.1038/s41598-021-98266-4
• Institution: Universiti Teknologi Malaysia

We report on magnetotransport in a high-quality graphene device, which is based on monolayer graphene (Gr) encapsulated by hexagonal boron nitride (hBN) layers, i.e., hBN/Gr/hBN stacks. In the vicinity of the Dirac point, a negative magnetoconductance is observed for high temperatures > ~ 40 K, whereas it becomes positive for low temperatures ≤ ~ 40 K, which implies an interplay of quantum interferences in Dirac materials. The elastic scattering mechanism in hBN/Gr/hBN stacks contrasts with that of conventional graphene on SiO2, and our ultra-clean graphene device shows nonzero magnetoconductance for high temperatures of up to 300 K.