ABSTRACT Rainbow Landau levels offer great opportunities for advanced multiplexed wave processing. To date, only rainbow flat Landau levels, which cannot propagate, have been realized, while their chiral counterparts, which can propagate, remain unachieved experimentally. Furthermore, the implementation of rainbow Landau levels in elastic systems—despite their strong potential for robust, parallel elastic wave processing—has yet to be achieved. Here, we realize rainbow Landau levels in an elastic meta‐device by synthesizing both pseudo‐magnetic and pseudo‐electric fields. The formation of rainbow Landau levels is theoretically derived. Multiplexed ultrasonic energy trappings within the bulk enabled by the rainbow Landau levels are experimentally demonstrated. By virtue of the robustness of Landau levels, the rainbow ultrasonic energy trappings along the customized route and within the curved meta‐device, which have never been realized before, are also experimentally exhibited. Our findings open avenues for developing innovative devices, including multifrequency ultrasonic dividers, wave‐based multiplexed parallel processors, and integrated elastic circuits with high‐volume communication capacities.
Chen et al. (Wed,) studied this question.