Signatures of hot carriers and hot phonons in the re-entrant metallic and semiconducting states of Moiré-gapped graphene
Abstract
Stacking of graphene with hexagonal boron nitride (h-BN) can dramatically modify its bands from their usual linear form, opening a series of narrow minigaps that are separated by wider minibands. While the resulting spectrum offers strong potential for use in functional (opto)electronic devices, a proper understanding of the dynamics of hot carriers in these bands is a prerequisite for such applications. In this work, we therefore apply a strategy of rapid electrical pulsing to drive carriers in graphene/h-BN heterostructures deep into the dissipative limit of strong electron-phonon coupling. By using electrical gating to move the chemical potential through the “Moiré bands”, we demonstrate a cyclical evolution between metallic and semiconducting states. This behavior is captured in a self-consistent model of non-equilibrium transport that considers the competition of electrically driven inter-band tunneling and hot-carrier scattering by strongly non-equilibrium phonons. Overall, our results demonstrate how a treatment of the dynamics of both hot carriers and hot phonons is essential to understanding the properties of functional graphene superlattices.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 17, 2023
- Source ID
- 10.1038/s41467-023-37292-4
Entities
People
- Bilal Barut
- Gil-Ho Kim
- Harihara Ramamoorthy
- Ishiaka Mansaray
- Jonathan P Bird
- Jong E. Han
- Jubin Nathawat
- Keke He
- Kenji Watanabe
- Kohei Sakanashi
- Miao Zhao
- Michael D. Randle
- Naoto Wada
- Nargess Arabchigavkani
- Nobuyuki Aoki
- Ratchanok Somphonsane
- Ripudaman Dixit
- Shenchu Yin
- Takashi Taniguchi
Organizations
- Air Force Office of Scientific Research
- United States Department of Energy