Robust topological rainbow trapping in shamrock-leaf phononic crystal plates

The topological properties of elastic waves underpin the visions of widespread novel phonon devices such as topological rainbow trapping. In this work, a shamrock-leaf perforated phononic crystal with a graded interface is designed to achieve both the topological edge states (TES) and rainbow effect together. The topological rainbow mechanism activated by varying TES along the gradient interface is uncovered, and spatial trapped waves of different frequencies are presented. Meanwhile, based on the topological rainbow effect, the wave packet behaviors encountering various types of defects at interfaces are observed. Furthermore, deviations from the original trapping position under different disturbance factors are investigated. This work provides a useful handle for piloting applications of topological phononic transports.