학술논문
Phonon-mediated room-temperature quantum Hall transport in graphene
Document Type
Working Paper
Author
Vaquero, Daniel; Clericò, Vito; Schmitz, Michael; Delgado-Notario, Juan Antonio; Martín-Ramos, Adrian; Salvador-Sánchez, Juan; Müller, Claudius S. A.; Rubi, Km; Watanabe, Kenji; Taniguchi, Takashi; Beschoten, Bernd; Stampfer, Christoph; Diez, Enrique; Katsnelson, Mikhail I.; Zeitler, Uli; Wiedmann, Steffen; Pezzini, Sergio
Source
Nature Communications 14, 318 (2023)
Subject
Language
Abstract
The quantum Hall (QH) effect in two-dimensional electron systems (2DESs) is conventionally observed at liquid-helium temperatures, where lattice vibrations are strongly suppressed and bulk carrier scattering is dominated by disorder. However, due to large Landau level (LL) separation (~2000 K at B = 30 T), graphene can support the QH effect up to room temperature (RT), concomitant with a non-negligible population of acoustic phonons with a wave-vector commensurate to the inverse electronic magnetic length. Here, we demonstrate that graphene encapsulated in hexagonal boron nitride (hBN) realizes a novel transport regime, where dissipation in the QH phase is governed predominantly by electron-phonon scattering. Investigating thermally-activated transport at filling factor 2 up to RT in an ensemble of back-gated devices, we show that the high B-field behaviour correlates with their zero B-field transport mobility. By this means, we extend the well-accepted notion of phonon-limited resistivity in ultra-clean graphene to a hitherto unexplored high-field realm.
Comment: 17 pages, 4 figures. Supplementary information available at https://doi.org/10.1038/s41467-023-35986-3
Comment: 17 pages, 4 figures. Supplementary information available at https://doi.org/10.1038/s41467-023-35986-3