Fig. 5. Classical cost to simulate the experiment.
a, The equivalent classical cost of the experiment, as quantified by the minimum bond dimension, χ*, for the classical simulation to maintain a higher fidelity than the experiment across all times, that is, for C > Fd (inset). We consider several classical algorithms (for example, time-evolving block decimation, TEBD45), all of which become impractical at moderate system sizes. This necessitates the introduction of our Lightcone-MPS algorithm (Supplementary Information), which reaches a maximum value of χ* = 3,400 for n = 60. b, Predicted MPS costs (simulation time, sampling time and peak memory usage) to operate at χ* as a function of the experimental per-atom fidelity (main text). Times are representative of a single 16-core node on the Caltech cluster (Supplementary Information).