Fig. 3.
Measured third-harmonic signal intensities in the nonlinear circuit. a, b Normalized third-harmonic signal intensity χ versus input frequency fin and input voltage Vin, for the a nontrivial lattice and b trivial lattice. Here, χ is derived from experimental data using the definition (6). c Ratio of the trivial and nontrivial intensities, χnontrivial/χtrivial, within the region indicated by boxes in a and b. d Measured third-harmonic intensities (normalized to the input signal) at different sites, for the three sets of input parameters indicated by stars in c: Vin = 0.5 V, 1.5 V, and 2.5 V, with fixed fin = 16 MHz