Fast and length-independent transport time supported by topological edge states in finite-size Su-Schrieffer-Heeger chains

TL;DR

This paper demonstrates experimentally that topological edge states in finite-size SSH chains enable fast, length-independent transport of optical information, leveraging wavefunction localization for robust and efficient communication.

Contribution

It provides the first experimental verification of length-independent transport time via topological edge states in photonic SSH chains, with implications for topological photonic devices.

Findings

Transport time is independent of chain length in 1D SSH models.

Edge states exhibit strong localization leading to faster transport.

Experimental measurements confirm theoretical predictions up to 20-site chains.

Abstract

In order to transport information with topological protection, we explore experimentally the fast transport time using edge states in one-dimensional Su-Schrieffer-Heeger (SSH) chains. The transport time is investigated in both one- and two-dimensional models with topological non-trivial band structures. The fast transport is inherited with the wavefunction localization, giving a stronger effective coupling strength between the mode and the measurement leads. Also the transport time in one-dimension is independent of the system size. To verify the asertion, we implement a chain of split-ring resonators and their complementary ones with controllable hopping strengths. By performing the measurements on the group delay of non-trivially topological edge states with pulse excitations, the transport time between two edge states is directly observed with the chain length up to $20$. Along the route to harness topology to protect optical information, our experimental demonstrations provide a crucial guideline for utilizing photonic topological devices.