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

Abstract

A recent experiment has observed a series of quantum-spin-Hall effects in moiré MoTe2. 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 MoTe2 bilayers. We use the continuum model with parameters relevant to twisted MoTe2 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 MoTe2 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.

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