Robust non-Abelian even-denominator fractional Chern insulator in twisted bilayer MoTe2

• Published in: Nature communications Vol. 16; no. 1; pp. 2115 - 9
• Main Authors: Chen, Feng, Luo, Wei-Wei, Zhu, Wei, Sheng, D. N.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.03.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1034/1038; 639/301/119/2792; 639/766/119/2794; Continuum modeling; Humanities and Social Sciences; Insulators; Magnetic fields; Molybdenum compounds; multidisciplinary; Parameters; Physics; Robustness; Science; Science (multidisciplinary); Symmetry; Tellurides; Transition metal compounds
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-025-57326-3

A recent experiment has observed a series of quantum-spin-Hall effects in moiré MoTe 2 . 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 2 bilayers. We use the continuum model with parameters relevant to twisted MoTe 2 bilayers and obtain three consecutive nearly flat Chern bands with the same Chern number. Crucially, when the second moiré miniband is half-filled, signatures of a non-Abelian fractional quantum-Hall state are found via exact diagonalization calculations, including a stable six-fold ground-state degeneracy that grows more robust with the lattice size and is consistent with an even-denominator fractional Chern insulator state. Our results signal the potential of realizing the non-Abelian state at zero magnetic field in twisted bilayer MoTe 2 at the fractional hole filling of 3/2. Recent experiments suggest the possibility of realizing fractional Chern insulators in twisted transition metal dichalcogenides. Here, the authors present numerics revealing a robust non-Abelian zero magnetic-field state that may be realized in twisted bilayer MoTe2 in a specific parameter range.