Tunable Topological Fano Resonances in Graphene-Based Nanomechanical Lattices

A topological Fano resonance with ultrasharp asymmetric line shape is sensitive to external parameters and is immune to structural disorder, and thus, acts as a robust sensor. Here, an ultracompact tunable on-chip integrated topological Fano resonance is designed based on graphene-based nanomechanical phononic crystals. The Fano resonance comes from the interference between topologically protected even and odd edge modes at the interface between trivial and nontrivial insulators. The two edge modes have different edge-mode widths, resulting in distinct resonant lifetimes. The resonant frequency can be adjusted by employing different gate voltages, which can vary the tension of the graphene membrane. Such tunable topological Fano resonances can be applied to design a wide variety of highly sensitive and accurate robust sensors, including extremely tiny forces, masses, and spatial positions.