Fig. 4: Experimental results of geometric-size-dependent non-Hermitian topological synchronization.
From: Observation of non-Hermitian topological synchronization
a The schematic diagram of the designed electric circuit to simulate the geometric-size-dependent topological synchronization. Two subcharts present the structure of a negative resistance and the non-reciprocal coupling. b The photograph image of twenty-five circuit cells in the fabricated circuit sample for simulating geometric-size-dependent synchronization. The right chart plots the enlarged photo of a single circuit cell. c1–c4 Colored lines show the measured voltage signals from four circuit nodes, corresponding to the four dots with matched colors in b, with \({N}_{x}={N}_{y}=5\). d1, d2 Measured results of time-domain voltage signals \({V}_{e}(t)={\sum }_{i\in {N}_{e}}{V}_{i}(t)/{N}_{e}\) and \({V}_{b}(t)={\sum }_{i\in {N}_{b}}{V}_{i}(t)/{N}_{b}\) of the steady of the system with \({N}_{x}={N}_{y}=5\). e1, e2 Measured voltage signals of a boundary site 68 and a bulk site 77 with \({N}_{x}=8,\,{{N}}_{y}=5\). The purple and orange dots in the inset indicate the locations of the measured voltage signals in the circuit lattice model. f1, f2 Measured results of time-domain voltage signals \({S}_{e}(t)\) and \({S}_{b}(t)\) of the steady of the system with \({N}_{x}=8,{N}_{y}=5\). g1, g2 The corresponding frequency spectra of the voltage signals \({S}_{e}(t)\) and \({S}_{b}(t)\). Here, other circuit parameters are set as Rb = 200Ω, Ru = 100Ω, R1 = 200Ω, R2 = 100Ω, C = 1000 nF, R3 = 5kΩ, R4 = 4 kΩ, and R5 = 796 kΩ.
