De Haas-van Alphen spectroscopy and magnetic breakdown in moiré graphene.

Autor: Bocarsly M; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel., Uzan M; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel., Roy I; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel., Grover S; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel., Xiao J; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel., Dong Z; Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA., Labendik M; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel., Uri A; Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA., Huber ME; Departments of Physics and Electrical Engineering, University of Colorado Denver, Denver, CO 80217, USA., Myasoedov Y; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel., Watanabe K; Research Center for Electronic and Optical Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan., Taniguchi T; Research Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan., Yan B; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel., Levitov LS; Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA., Zeldov E; Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel.
Jazyk: angličtina
Zdroj: Science (New York, N.Y.) [Science] 2024 Jan 05; Vol. 383 (6678), pp. 42-48. Date of Electronic Publication: 2024 Jan 04.
DOI: 10.1126/science.adh3499
Abstrakt: Quantum oscillations originating from the quantization of electron cyclotron orbits provide sensitive diagnostics of electron bands and interactions. We report on nanoscale imaging of the thermodynamic magnetization oscillations caused by the de Haas-van Alphen effect in moiré graphene. Scanning by means of superconducting quantum interference device (SQUID)-on-tip in Bernal bilayer graphene crystal axis-aligned to hexagonal boron nitride reveals large magnetization oscillations with amplitudes reaching 500 Bohr magneton per electron in weak magnetic fields, unexpectedly low frequencies, and high sensitivity to superlattice filling fraction. The oscillations allow us to reconstruct the complex band structure, revealing narrow moiré bands with multiple overlapping Fermi surfaces separated by unusually small momentum gaps. We identified sets of oscillations that violate the textbook Onsager Fermi surface sum rule, signaling formation of broad-band particle-hole superposition states induced by coherent magnetic breakdown.
Databáze: MEDLINE
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