Kagome Quantum Oscillations in Graphene Superlattices.

de Vries, Folkert K; Slizovskiy, Sergey; Tomić, Petar; Krishna Kumar, Roshan; Garcia-Ruiz, Aitor; Zheng, Giulia; Portolés, Elías; Ponomarenko, Leonid A et al. · Nano Lett · 2024

basic_science · Level V

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Abstract

Electronic spectra of solids subjected to a magnetic field are often discussed in terms of Landau levels and Hofstadter-butterfly-style Brown-Zak minibands manifested by magneto-oscillations in two-dimensional electron systems. Here, we present the semiclassical precursors of these quantum magneto-oscillations which appear in graphene superlattices at low magnetic field near the Lifshitz transitions and persist at elevated temperatures. These oscillations originate from Aharonov-Bohm interference of electron waves following open trajectories that belong to a kagome-shaped network of paths characteristic for Lifshitz transitions in the moire superlattice minibands of twistronic graphenes.