Topological heavy-tailed networks

TL;DR

This paper introduces topological heavy-tailed networks, demonstrating how complex, aperiodic networks like the Apollonian network can host topological phases, bridging topological physics and network science.

Contribution

It develops a tight-binding model and a gauge field assignment for the Apollonian network, revealing new topological phenomena in complex, aperiodic networks.

Findings

Identification of topological phases in the Apollonian network

Development of a spectral localizer method for topological characterization

Sensitivity of topological features governed by lower-degree nodes

Abstract

Although two-dimensional periodic structures have functioned as the primary platform for exploring topological phenomena, recent advances have substantially expanded this research boundary to include more intricate, aperiodic structures: quasicrystals, fractals, non-Euclidean lattices, and disordered materials. A network-based perspective not only offers a unified framework for classifying these diverse platforms based on their network connectivity but also unveils unexplored regimes of topological phenomena in complex networks. Here, we implement topological heavy-tailed networks, as an example of high-degree complex networks exhibiting topological phases. By developing a tight-binding model for the Apollonian network and a deterministic algorithm to assign nontrivial gauge fields to this aperiodic geometry, we compute the magnetic-flux-dependent energy spectrum: the Apollonian butterfly. Using spectral localizers, we characterize the topological features of the Apollonian butterfly, whose sensitivity is governed by lower-degree nodes, analogous to the controllability of complex networks. Our framework bridges topological physics and network science, introducing a connectivity-driven paradigm for the control of topological waves.