Recent experimental discovery of fractional Chern insulators at zero magnetic field in moiré superlattices has sparked intense interests in bringing Landau level physics to flat Chern bands. In twisted MoTe_{2} bilayers (tMoTe_{2}), recent theoretical and experimental studies have found three consecutive flat Chern bands at twist angle ∼2°. In this Letter, we investigate whether higher Landau level physics can be found in these consecutive Chern bands. At twist angles 2.00° and 1.89°, we identify four consecutive C=1 bands for the K valley in tMoTe_{2}. By constructing Wannier functions directly from density functional theory (DFT) calculations, a six-orbital model is developed to describe the consecutive Chern bands, with the orbitals forming a honeycomb lattice. Exact diagonalization on top of Hartree-Fock calculations are carried out with the Wannier functions. Especially, when the second moiré miniband is half-filled, signatures of non-Abelian states are found. Our Wannier-based approach in modeling moiré superlattices is faithful to DFT wave functions and can serve as benchmarks for continuum models. The possibility of realizing non-Abelian anyons at zero magnetic field also opens up a new pathway for fault-tolerant quantum information processing.
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http://dx.doi.org/10.1103/PhysRevLett.134.076503 | DOI Listing |
Phys Rev Lett
February 2025
University of Washington, Department of Materials Science and Engineering, Seattle, Washington 98195, USA.
Nat Commun
March 2025
Department of Physics and Astronomy, California State University Northridge, Northridge, California, USA.
A recent experiment has observed a series of quantum-spin-Hall effects in moiré MoTe. Among them, the vanishing Hall signal at the filling factor ν = 3 implies a possible realization of a time-reversal pair of even-denominator fractional Chern insulators. Inspired by this discovery, we numerically investigate whether a robust incompressible quantum-Hall liquid can be stabilized in the half-filled Chern band of twisted MoTe bilayers.
View Article and Find Full Text PDFACS Nano
March 2025
School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
Chern insulator (CI) exhibits rich physics with great interest in both theory and experiment. Here, we focus on the honeycomb and kagome ferromagnets and demonstrate that coupling the nontrivial electronic and magnonic bands allows for the dual CIs, where the quantum anomalous Hall effect and its bosonic analogue, i.e.
View Article and Find Full Text PDFPhys Rev Lett
February 2025
University of Tennessee, Department of Physics and Astronomy, Knoxville, Tennessee 37996, USA.
We investigate the moiré band structures and a possible even-denominator fractional quantum Hall state in small angle twisted bilayer MoTe_{2}, using combined large-scale local basis density functional theory calculation and continuum model exact diagonalization. Via large-scale first-principles calculations at θ=1.89°, we find a sequence of C=1 (Chern number in the K valley) moiré Chern bands in analogy to Landau levels.
View Article and Find Full Text PDFAdv Mater
February 2025
Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai, 400005, India.
Exploring the topological characteristics of electronic bands is essential in condensed matter physics. Moiré materials featuring flat bands provide a versatile platform for engineering band topology and correlation effects. In moiré materials that break either time-reversal symmetry or inversion symmetry or both, electronic bands exhibit Berry curvature hotspots.
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