Extended Data Fig. 2: Ablation study to quantify the impact of search and policy training.

Distribution of the relative error (NMAE) for stress-strain inverse design on the (a) 90:5:5 split test set, (b) user-defined target curves, and (c) energy absorbing-oriented target curves. Distribution of the accuracy for wave transmission inverse design on the (d) 90:5:5 split test set, (e) user-defined target sequences, and (f) noise control-oriented target responses. The relative error and accuracy are computed between the predicted responses of the generated metamaterials and the target responses. These results demonstrate how all components, from IL to RL and MCTS, contribute to the performance of our model.