Extended Data Figure 1: Time dependence of magnetic correlations for near-resonant driving.
From: Enhancement and sign change of magnetic correlations in a driven quantum many-body system
Nearest-neighbour spin–spin correlator C for the same lattice configuration as in Fig. 3, as a function of the modulation time after the ramp up of the drive. The data allow us to compare the formation and decay of magnetic correlations for two specific sets of interactions and modulation frequencies with the level of correlations in the static case (black). For a driving strength of K0 = 1.30(3) and with U/h = 3.8(1) kHz and ω/(2π) = 3 kHz (red), antiferromagnetic correlations increase with time and reach a level higher than the static case (black, U/h = 3.8(1) kHz). If the interaction is smaller than the driving frequency (blue, U/h = 4.4(1) kHz, ω/(2π) = 6 kHz), then the correlations switch sign and become ferromagnetic after a few milliseconds. For long times, the correlations in each configuration decrease as a result of heating in the lattice. Solid lines show exponential fits of the full data in the static case (grey) and to modulation times longer than 4 ms in the driven lattice for U > ħω (red). The difference between the data and the dashed component of the fit (red) indicates an initial increase in the correlations. The extracted lifetimes decrease from 82(34) ms without drive to 12(4) ms at K0 = 1.30(3). All measurements are averaged over one modulation cycle. Data points and error bars denote the mean and standard error of 13 individual measurements at different times within one driving period (see Methods).
