Topologically switchable transport in a bundled cable of wires

TL;DR

This paper demonstrates that a bundle of metallic wires interconnected by topological or trivial Su-Schrieffer-Heeger chains can switch from insulating to metallic behavior, with topological interconnects enabling robust, localization-free transport.

Contribution

It introduces a minimal model of a wire bundle with topological interconnects, revealing topologically induced metallic phases in disordered networks and analyzing their transport properties.

Findings

Topological interconnects induce a transition from insulator to metal.

The system exhibits ballistic conductance scaling linearly with wire number.

Zero-energy modes act as effective random dimers affecting localization.

Abstract

Advances in the next generation of mesoscopic electronics require an understanding of topological phases in inhomogeneous media and the principles that govern them. Motivated by the nature of motifs available in printable conducting inks, we introduce and study quantum transport in a minimal model that describes a bundle of one-dimensional metallic wires that are randomly interconnected by semiconducting chains. Each of these interconnects is represented by a Su-Schrieffer-Heeger chain, which can reside in either a trivial or a topological phase. Using a tight-binding approach, we show that such a system can transit from an insulating phase to a robust metallic phase as the interconnects undergo a transition from a trivial to a topological phase. In the latter, despite the random interconnectedness, the metal evades Anderson localization and exhibits a ballistic conductance that scales linearly with the number of wires. We show that this behavior originates from hopping renormalization in the wire network. The zero-energy modes of the topological interconnects act as effective random dimers, giving rise to an energy-dependent localization length that diverges as $\sim 1/E^2$. Our work establishes that random networks provide a yet-unexplored platform to host intriguing phases of topological quantum matter.