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arXiv · 2301.08674

Phonon-mediated room-temperature quantum Hall transport in graphene

Daniel Vaquero·Vito Clericò·Michael Schmitz·Juan Antonio Delgado-Notario·Adrian Martín-Ramos·Juan Salvador-Sánchez·Claudius S. A. Müller·Km Rubi·Kenji Watanabe·Takashi Taniguchi·Bernd Beschoten·Christoph Stampfer·Enrique Diez·Mikhail I. Katsnelson·Uli Zeitler·Steffen Wiedmann·Sergio Pezzini
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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.

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Daniel Vaquero, Vito Clericò, Michael Schmitz, Juan Antonio Delgado-Notario, Adrian Martín-Ramos, Juan Salvador-Sánchez, Claudius S. A. Müller, Km Rubi, Kenji Watanabe, Takashi Taniguchi, Bernd Beschoten, Christoph Stampfer, Enrique Diez, Mikhail I. Katsnelson, Uli Zeitler, Steffen Wiedmann, Sergio Pezzini. 2023-01-20. Phonon-mediated room-temperature quantum Hall transport in graphene. https://doi.org/10.1038/s41467-023-35986-3

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