Extended Data Fig. 4: Comparison between spectra \(\widetilde{{\boldsymbol{\xi }}}({\boldsymbol{\delta }}{\boldsymbol{\omega }},{\boldsymbol{t}})\) and \(\mathop{{\boldsymbol{\xi }}}\limits^{\approx }({\boldsymbol{\delta }}{\boldsymbol{\omega }},{\boldsymbol{t}})\).
From: Non-Abelian lattice gauge fields in photonic synthetic frequency dimensions
The definitions of \(\widetilde{\xi }\) and \(\mathop{\xi }\limits^{\approx }\) can be found in the Methods section. (a) The resonance features in \(\widetilde{\xi }\) near δω = 0. (b) The resonance features in \(\widetilde{\xi }\) near δω = 0.5 ΩR. (c) The quantity \(\mathop{\xi }\limits^{\approx }\) as defined in equation (19) in the Methods section. (a) and (b) are experimentally obtained with φ = 0, g = 0.14 ΩR, and vertically polarized input light. (c) is obtained by averaging (a) and (b), and is a replica of Fig. 3d. The colour scale is normalized to [0, 1] for each individual subplot.
