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.