Fig. 5: Experimental observation of edge states in the mass dimer and mechanical Kitaev chain.
From: Strain topological metamaterials and revealing hidden topology in higher-order coordinates
a Schematic of the experimental mass-dimer setup with free boundary conditions. b Measured frequency response at particle #8 when the chain is excited from the left side (#1, smaller mass) or from the right side (#14, larger mass). The shaded area corresponds to the band gap. c Measured amplitudes of the edge state (displayed in displacement coordinates) localized at the boundary ending with small mass and P = 0.4. d Schematic of the mechanical Kitaev chain, suspended vertically by fixing particle #1. Three points are probed on each particle to characterize the transverse displacement and rotation. e Measured frequency response at particle #7 when the chains with P = 1.5 and P = 2.5 are excited at the fixed end (particle #2) or at the free end (particle #13). The shaded areas correspond to the band gap. Measured amplitudes of the edge state (displayed in displacement coordinates) localized at the fixed boundary for P = 1.5 (f), and at the free boundary for P = 2.5 (g). Error bars denote the variation (one standard deviation from averaged value) in experimental measurements.
