Detection of graphene’s divergent orbital diamagnetism at the Dirac point

J Vallejo Bustamante (1) , N J Wu (1, 2) , C Fermon (3) , M Pannetier-Lecoeur (3) , T Wakamura (4, 1) , K Watanabe (5) , T Taniguchi (6) , T Pellegrin (1) , A Bernard (1) , S Daddinounou (1) , V Bouchiat (7) , S Guéron (1) , M Ferrier (1) , G Montambaux (1) , H Bouchiat (1)

1 LPS - Laboratoire de Physique des Solides
2 ISMO - Institut des Sciences Moléculaires d'Orsay
3 SPEC - UMR3680 - Service de physique de l'état condensé
4 NTT Basic Research Laboratories [Tokio]
5 Research Center for Functional Materials
6 WPI-MANA - International Center for Materials Nanoarchitectonics
7 NEEL - Quan2m - Interactions modulables dans des états quantiques 2D

The electronic properties of graphene have been intensively investigated over the past decade. However, the singular orbital magnetism of undoped graphene, a fundamental signature of the characteristic Berry phase of graphene's electronic wave functions, has been challenging to measure in a single flake. Using a highly sensitive giant magnetoresistance (GMR) sensor, we have measured the gate voltage-dependent magnetization of a single graphene monolayer encapsulated between boron nitride crystals. The signal exhibits a diamagnetic peak at the Dirac point whose magnetic field and temperature dependences agree with long-standing theoretical predictions. Our measurements offer a means to monitor Berry phase singularities and explore correlated states generated by the combined effects of Coulomb interactions, strain, or moiré potentials.

Domaines: Physique [physics]

J Vallejo Bustamante, N J Wu, C Fermon, M Pannetier-Lecoeur, T Wakamura, et al.. Detection of graphene’s divergent orbital diamagnetism at the Dirac point. Science, 2021, 374 (6573), pp.1399 - 1402. ⟨10.1126/science.abf9396⟩. ⟨hal-03531860⟩