Subwavelength robust waveguiding with chiral metamaterial waveguides

In this work, we design and experimentally demonstrate in the microwave range a robust metamaterial waveguide, which is formed at the boundary between two locally resonant chiral metamaterials with opposite chirality. We show that the interface states at such boundary are inherently robust to disorder in both the position and resonance frequency of subwavelength resonators. Moreover, we quantitatively demonstrate the superiority of the proposed subwavelength waveguiding over previously proposed designs, including frequency-defect lines, symmetry-based topological edge modes, and Valley-Hall interface states.