Visualizing Electronic Structure of Twisted Bilayer MoTe2 in Devices
arXiv:2509.09080 · doi:10.1038/s42005-026-02497-8
Abstract
The pursuit of emergent quantum phenomena lies at the forefront of modern condensed matter physics. A recent breakthrough in this arena is the discovery of the fractional quantum anomalous Hall effect (FQAHE) in twisted bilayer MoTe2 (tbMoTe2), marking a paradigm shift and establishing a versatile platform for exploring the intricate interplay among topology, magnetism, and electron correlations. While significant progress has been made through both optical and electrical transport measurements, direct experimental insights into the electronic structure - crucial for understanding and modeling this system - have remained elusive. Here, using spatially and angle-resolved photoemission spectroscopy (μ-ARPES), we directly map the electronic band structure of tbMoTe2. We identify the valence band maximum, whose partial filling underlies the FQAHE, at the K points, situated approximately 150 meV above the Γ valley. By fine-tuning the doping level via in-situ alkali metal deposition, we also resolve the conduction band minimum at the K point, providing direct evidence that tbMoTe2 exhibits a direct band gap - distinct from all previously known moire bilayer transition metal dichalcogenide systems. These results offer critical insights for theoretical modeling and advance our understanding of fractionalized excitations and correlated topological phases in this emergent quantum material.
13 pages, 4 figures
References in corpus (28)
- The SIESTA method for ab initio order-N materials simulation
- Efficient index handling of multidimensional periodic boundary conditions
- Van der Waals heterostructures
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Optimized norm-conserving Vanderbilt pseudopotentials
- Deep Potential Molecular Dynamics: a scalable model with the accuracy of quantum mechanics
- DeePMD-kit: A deep learning package for many-body potential energy representation and molecular dynamics
- High temperature fractional quantum Hall states
- Fractional quantum Hall states at zero magnetic field
- Topological insulators in twisted transition metal dichalcogenide homobilayers
- Signatures of Fractional Quantum Anomalous Hall States in Twisted MoTe2 Bilayer
- Observation of Fractionally Quantized Anomalous Hall Effect
- Fractional quantum Hall effect in the absence of Landau levels
- Fractional Chern Insulator
- Moiré heterostructures as a condensed matter quantum simulator
- Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
- Integer and fractional Chern insulators in twisted bilayer MoTe2
- Mapping the twist angle and unconventional Landau levels in magic angle graphene
- Directly visualizing the momentum forbidden dark excitons and their dynamics in atomically thin semiconductors
- Visualization of the flat electronic band in twisted bilayer graphene near the magic angle twist
- A Microscopic Perspective on Moiré Materials
- Renormalization of quasiparticle band gap in doped two-dimensional materials from many-body calculations
- Microfocus laser-ARPES on encapsulated mono-, bi-, and few-layer 1T'-WTe
- Strong Inter-valley Electron-Phonon Coupling in Magic-Angle Twisted Bilayer Graphene
- Direct observation of minibands in twisted heterobilayers
- Observation of flat moiré bands in twisted bilayer WSe
- Signatures of unconventional superconductivity near reentrant and fractional quantum anomalous Hall insulators
- Direct Measurement of the Electronic Structure and band gap nature of atomic-layer-thick 2H-MoTe2