Supplementary Information: Infrared Spectroscopy forDiagnosing Superlattice Minibands in Twisted BilayerGraphene near the Magic-angle

Twisted bilayer graphene (TBG) represents a highly tunable, strongly correlated electron system. However, understanding the single-particle band structure alone has been challenging due to a lack of spectroscopic measurements over a broad energy range. Here, we probe the band structure of TBG around...

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Detalles Bibliográficos
Autores: Li, Geng, Krishna Kumar, Roshan, Stepanov, Petr, Pantaleón, Pierre A., Zhan, Zhen, Agarwal, Hitesh, Bercher, Adrien, Barrier, Julien, Watanabe, Kenji, Taniguchi, Takashi, Kuzmenko, Alexey B, Guinea, Francisco, Torre, Iacopo, Koppens, Frank H. L.
Tipo de recurso: conjunto de datos
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::b19c966d22270aa0e01dca7509d9cda4
Acceso en línea:http://hdl.handle.net/10261/384406
Access Level:acceso abierto
Palabra clave:wide angular range
reveal spectral features
intralayer tunneling parameters
find good agreement
diagnosing superlattice minibands
connect spectral features
broad energy range
twist angle
spectroscopic measurements
screening heterostructures
quantum transport
optical fingerprint
measurements offer
magic angle
lattice relaxation
interband transitions
infrared spectroscopy
highly tunable
continuum model
challenging due
better defined
band structure
analysis suggests
Descripción
Sumario:Twisted bilayer graphene (TBG) represents a highly tunable, strongly correlated electron system. However, understanding the single-particle band structure alone has been challenging due to a lack of spectroscopic measurements over a broad energy range. Here, we probe the band structure of TBG around the magic angle using infrared spectroscopy and reveal spectral features that originate from interband transitions. In combination with quantum transport, we connect spectral features over a broad energy range (10–700 meV) and track their evolution with the twist angle. We compare our data with calculations of the band structures obtained via the continuum model and find good agreement only when considering a variation of interlayer/intralayer tunneling parameters with the twist angle. Our analysis suggests that the magic angle also shifts due to lattice relaxation and is better defined for a wide angular range of 0.9–1.1°. Additionally, our measurements offer an optical fingerprint of the magic angle for screening heterostructures before nanofabrication.