Accelerated Topological Pumping in Photonic Waveguides Based on Global Adiabatic Criteria

TL;DR

This paper introduces a global adiabatic criterion enabling faster topological pumping in photonic waveguides, achieving high fidelity with reduced device length and demonstrating robustness across a broad bandwidth.

Contribution

It develops a universal global adiabatic framework and experimentally validates accelerated topological pumping in photonic waveguides with improved speed and robustness.

Findings

Achieved >0.95 fidelity with fivefold device length reduction

Demonstrated linear scaling of fidelity with system size

Maintained performance over 400 nm bandwidth

Abstract

Adiabatic topological pumping enables robust transport of energy and information, yet its operational speed is fundamentally constrained by the instantaneous adiabatic condition, which necessitates prohibitively slow parameter variations. Here, we propose a paradigm shift from instantaneous to global adiabaticity. We derive a global adiabatic criterion (GAC) that establishes an absolute fidelity bound by controlling the root-mean-square nonadiabaticity. Building on this framework, we introduce a fluctuation-suppression acceleration criterion to minimize spatial inhomogeneity, allowing for a safe increase in mean nonadiabaticity without compromising fidelity. We experimentally demonstrate this principle in femtosecond-laser-written photonic Su-Schrieffer-Heeger waveguide arrays via scalable power-law coupling modulation. Our accelerated topological pumping achieves a fidelity of >0.95 with a fivefold reduction in device length compared to conventional schemes, exhibits the predicted linear scaling with system size, and maintains robust performance across a bandwidth exceeding 400 nm. This GAC framework provides a universal design rule for fast, compact, and robust adiabatic devices across both quantum and classical topological platforms.