Berlin 2024 – scientific programme
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O: Fachverband Oberflächenphysik
O 53: 2D Materials IV: Graphene (joint session O/TT)
O 53.4: Talk
Wednesday, March 20, 2024, 16:00–16:15, MA 005
Visualizing band hybridization and moiré effects in gate-tunable twisted graphene layers using nanoARPES — •Zhihao Jiang1, Kimberly Hsieh1, Paulina Majchrzak1, Alfred Jones1, Chakradhar Sahoo1, Youngju Park2, Dongkyu Lee2, Kenji Watanabe3, Takashi Taniguchi3, Jill Miwa1, Jeil Jung2, Yong P. Chen1, and Søren Ulstrup1 — 1Aarhus University, Denmark — 2University of Seoul, Korea — 3National Institute for Materials Science, Japan
Twisted graphene layers have emerged as an intriguing class of quantum materials that display surprising correlation effects, including superconductivity, Mott insulators as well as strange metal phases. The possibility to tune these states using twist angle and electrostatic doping provides a promising route to interrogate the underpinning interactions between the electronic states. Here, we use angle-resolved photoemission spectroscopy with spatial resolution at the new micro- and nanoARPES branch at the ASTRID2 synchrotron light source at Aarhus University in Denmark to visualize the electronic states of twisted graphene layers integrated in device architectures. Specifically, we reveal the flat bands in twisted bilayer and double-bilayer graphene around the magic angles and systematically track the evolution of hybridization effects and moiré bands with small twist angles up to 6∘. The interactions in the systems are further tuned by in situ electrostatic doping using a back-gate electrode. Our study paves the way for directly engineering band structure and correlation effects in twisted two-dimensional materials.
Keywords: ARPES; graphene; twistronic; 2D material