Determine whether electronic properties are governed by an approximate 2D superlattice or a strictly 1D superlattice

Determine whether the electronic properties of the bulk foliated superlattice Sr–Ta–S aperiodic composite crystals STS(n, φ)—composed of alternating TaS2 and Sr6TaS8 layers and exhibiting an in-plane incommensurate modulation—are governed by an approximate two-dimensional superlattice (i.e., a 2D approximant arising from lattice aliasing) or by a strictly one-dimensional superlattice along the incommensurate a-axis.

Background

The paper introduces a family of bulk foliated superlattice materials denoted STS(n, φ), built from intergrown TaS2 and Sr6TaS8 layers that are commensurate along b but incommensurate along a, producing a tunable in-plane modulation. Structural characterizations (WAXS, SCXRD, HAADF-STEM) indicate that some members are strictly 1D-modulated along a, while others—though strictly 1D in construction—exhibit lattice aliasing along b that makes them resemble 2D superlattice approximants.

Because electronic structure is highly sensitive to the periodicity and dimensionality of the underlying modulation, the authors highlight that it is currently unresolved whether transport and Fermiology in these materials are better captured by an approximate 2D superlattice description (akin to moiré approximants) or by a strictly 1D superlattice description. They explicitly note that this question will be investigated in future work.