Microscopic conditions for anomalous hysteresis

Determine the precise conditions that produce anomalous hysteresis in graphene/hexagonal-boron-nitride heterostructures, including the role of rotational alignment between the hexagonal-boron-nitride layers.

Background

One θ=1.33° device exhibits anomalous hysteresis and electron-ratchet behavior in its gate map. Previous work has linked this phenomenon to rotational alignment between the hexagonal-boron-nitride layers, but the supplementary discussion states that the precise conditions responsible for the behavior remain unknown. The authors operated the device so that this unresolved effect did not affect the paper’s conclusions.

References

This anomalous hysteresis effect is known to occur in some graphene/hBN heterostructures and has been linked to the rotational alignment between the hexagonal boron nitride layers within the heterostructure, although the precise conditions leading to the behavior remain unknown.

— Incipient superconductivity and tunable Chern insulators in twisted Bernal bilayer-trilayer graphene  (2609.30202 - Waleffe et al., 24 Sep 2026) in Supplementary Materials, Methods, subsection “Anomalous hysteresis in a θ=1.33° device”