Fig. 1: Floquet engineering of spin bonds and topological edge-states.
From: Floquet control of interactions and edge states in a programmable quantum simulator
a–c Bond dimerization in an L = 12 spin crystal. Measured spin-spin bond strength \(\hslash | {{{{\mathcal{J}}}}}_{ij}|\) between ith and jth spins up to next-nearest neighbors (NNN) with increasing Floquet amplitude \(\bar{\eta }\). a No modulation (\(\bar{\eta }=0\)). b Moderate modulation (\(\bar{\eta }=0.6\)). c Full modulation (\(\bar{\eta }=1\)). Black spheres for spins and lines for bonds strength, pink rectangles for local Floquet fields. d–f Evolution of a single spin excitation at the edge over time for configurations (a–c) respectively. The Floquet field suppresses thermalization into the bulk, leading to edge localization. J: average nearest-neighbor spin bond coupling absent the Floquet drive; yellow lines show excitation spreading rate (see “Methods”). g spin excitation at the crystal edge \(\langle {\hat{s}}_{z}^{(1)}\rangle\) with varying Floquet field amplitude. h Excitation spreading rate vs (black circles) decreases with increasing Floquet field amplitude, consistent with the modified SSH model (Eq. (1), purple) and the numerical time-dependent ion Hamiltonian (Eq. (2), green). Bars represent 1σ binomial uncertainties. Data in d–f aligns with both numerical models in Supplementary Fig. 2.
