Interplay of Landau quantization and interminivalley scatterings in a weakly coupled moiré superlattice
arXiv:2401.12003 · doi:10.1021/acs.nanolett.4c01411
Abstract
Double layer quantum systems are promising platforms for realizing novel quantum phases. Here, we report a study of quantum oscillations (QOs) in a weakly coupled double layer system, composed of a large angle twisted double bilayer graphene (TDBG). We observe two different QOs at low temperature, one with a periodicity in carrier density (n), i.e. Shubnikov de Haas oscillation (SdHO) due to Landau quantization, and the other one in displacement field (D), resulting a grid pattern. We quantify the interlayer coupling strength by measuring the interlayer capacitance from the grid pattern with a capacitance model, revealing an electron hole asymmetry. At high temperature when SdHO are thermal smeared, we observe resistance peaks when LLs from two minivalleys in the moiré Brillion zone are aligned, regardless of carrier density; eventually, it results in a two fold increase of oscillating frequency in D, serving as a smoking gun evidence of the magneto intersubband oscillations (MISO) in a double layer system. The temperature dependence of MISO suggests electron-electron interaction between two minivalleys play a crucial rule in the scattering, and the scattering times obtained from MISO thermal damping are found to be correlated with the interlayer coupling strength. Our study reveals an intriguing interplay among Landau quantization, moiré band structure, and scatterings.
References in corpus (16)
- Tunable Phase Boundaries and Ultra-Strong Coupling Superconductivity in Mirror Symmetric Magic-Angle Trilayer Graphene
- High-temperature superfluidity with indirect excitons in van der Waals heterostructures
- Strongly correlated excitonic insulator in atomic double layers
- Band structure and topological property of twisted double bilayer graphenes
- Crossover between Strongly-coupled and Weakly-coupled Exciton Superfluids
- Isospin competitions and valley polarized correlated insulators in twisted double bilayer graphene
- Strong interminivalley scattering in twisted bilayer graphene revealed by high-temperature magnetooscillations
- Odd integer quantum Hall states with interlayer coherence in twisted bilayer graphene
- Magneto-intersubband oscillations in two dimensional systems with energy spectrum split due to spin-orbit interaction
- Scattering between minivalleys in a moiré material
- Theory of Difference Frequency Quantum Oscillations
- Temperature-linear Resistivity in Twisted Double Bilayer Graphene
- Thermally activated intersubband scattering and oscillating magnetoresistance in quantum wells
- Quantum capacitive coupling between large-angle twisted graphene layers
- Observation of first-order quantum phase transitions and ferromagnetism in twisted double bilayer graphene
- Quantum oscillations in field-induced correlated insulators of a moiré superlattice