Regensburg 2022 – scientific programme
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O: Fachverband Oberflächenphysik
O 72: 2D Materials 3: hBN and Electronic Structure
O 72.4: Talk
Thursday, September 8, 2022, 15:45–16:00, S052
Nanoscale view of massive Dirac quasiparticles in lithographic superstructures — •Alfred Jones1, Lene Gammelgaard2, Deepnaryan Biswas1, Mikkel Sauer3, Roland Koch4, Chris Jozwiak4, Eli Rotenberg4, Aaron Bostwick4, Kenji Watanabe5, Takashi Taniguchi5, Cory Dean6, Thomas Pedersen3, Antti-Pekka Jauho2, Peter Bøggild2, Bjarke Jessen6, and Søren Ulstrup1 — 1Aarhus University, Denmark — 2Technical University of Denmark, Denmark — 3Aalborg University, Denmark — 4Advanced Light Source, USA — 5National Institute for Materials Science, Japan — 6Columbia University, USA
Massive Dirac quasiparticles play a central role in a number of emerging physical phenomena such as topological phase transitions and anomalous Hall effects. Single-layer graphene appears to be an ideal platform to explore such properties, however engineering the transition from massless to massive Dirac quasiparticles in a controllable fashion remains a significant challenge. Here, we employ angle-resolved photoemission with a nanoscale light spot (nanoARPES) to directly measure the electronic structure modifications induced by lithographic patterning of an antidot superlattice onto a graphene device. We observe a transition from massless Dirac fermions in the pristine graphene to a massive character in patterned regions, and determine that the mass scales linearly with antidot diameter, consistent with theory. Gate-induced electron-doping of the patterned graphene produces an enhancement of the mass, highlighting the versatility of nanopatterned graphene as a platform for engineering such quasiparticles.