Why the zero-field 1/3 state is weaker than the 2/3 state · revision history

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Title

Why the zero-field $1/3$ state is weaker than the $2/3$ state

Plain

In twisted MoTe2 the zero-field fractional Hall state at two thirds band filling is clear in transport while the one-third state is fragile or absent, the reverse of the ordinary fractional quantum Hall effect, where one third is the strongest.

Precise

In twisted bilayer MoTe2 at $\theta \sim 3.5-3.9\,\mathrm{deg}$, fractional quantum anomalous Hall states are seen in transport at hole fillings $\nu = -2/3$ and $-3/5$ of the first Chern band (Cai et al., Park et al., Zeng et al., Nature 2023), while at $\nu = -1/3$ only optical signatures of a fragile state over a narrow displacement-field range have been reported (arXiv:2602.04561). Explain this asymmetry: mixing with the second moire band, Berry-curvature and quantum-metric inhomogeneity, or interaction-induced band renormalization favouring a charge-density wave at $1/3$. An answer is a calculation with independently fixed parameters reproducing the ground state and gap at each filling and its displacement-field range.

Settled by

Band-mixing-inclusive exact diagonalization or DMRG with independently fixed interaction parameters predicting the $\nu = -1/3$ ground state and gap, checked against transport and local imaging of charge order at that filling.

Kind

phenomenon

Answer type

mechanism

References

(empty)

Literature status

open

Status note

Optical evidence for a fragile $-1/3$ state appeared in 2026 (arXiv:2602.04561); several 2023-2025 calculations point to band mixing and band renormalization, without consensus as of 2026, to this survey's knowledge.

Posed since

2023