Electron Model on Truchet Tiling: Extended-to-Localized Transitions, Mobility Edge, and Asymmetric Spectrum

TL;DR

This paper studies electron localization in disordered Truchet-tiling structures, revealing phase transitions, mobility edges, and spectral asymmetries, with implications for quantum materials and photonic systems.

Contribution

It introduces a novel electron model on random Truchet tilings, demonstrating phase transitions and spectral features not previously characterized in such disordered systems.

Findings

Successive phase transitions from extended to localized states

Identification of mobility edges through fractal dimension analysis

Asymmetry and shift in van Hove singularities as spectral signatures

Abstract

Motivated by recent advances in the realization of Truchet-tiling structures in molecular networks and metal-organic frameworks, we investigate the wave localization issue in this kind of structure. We introduce an electron model based on random Truchet tilings-square lattices with randomly oriented diagonal links-and uncover a rich interplay between spectral and localization phenomena. By varying the strength of diagonal couplings, we demonstrate successive transitions from an extended phase, through a regime with a mobility edge, to a fully localized phase. The energy-resolved fractal dimension analysis captures the emergence and disappearance of mobility edges, while an anomalous shift and asymmetry in the van Hove singularity are identified as key signatures of the underlying disordered Truchet-tiling structure. Our findings position Truchet-tiled electron systems as a versatile platform for engineering disorder-driven localization and interaction effects in amorphous quantum materials and photonic architectures.