Electronic band properties of graphene on SrTiO₃

Graphene on SrTiO₃ (STO) substrate is a promising platform for emerging exotic quantum phenomena (e. g. quantum Hall ferromagnetism [1] and charge-density-wave order [2]) owing to the large dielectric permittivity of STO that significantly screens the electron-electron interaction in graphene. Additionally, the use of STO as a back-gate material allows doping of a substantial number of carriers and, therefore, investigation of the electronic band structure of graphene at high energies (> 1 eV). To study the electronic band properties of graphene in a weakly interacting electron environment, we measured electrical transport on graphene/STO in high magnetic fields up to 60 T and a wide temperature range of 1.5 – 300 K. In this talk, we will present findings inferred from the quantum Hall effect and quantum oscillations results on graphene/STO devices. Our detailed investigation on back-gate and temperature dependence of quantum Hall effect and quantum oscillations suggests a strong impact of STO substrate on the Fermi level of graphene.

References:

[1] L. Veyrat et al., Science 367, 781 (2020).

[2] A. Coissard et al., Nature 605, 51 (2022).