通过从实验和理论方面对声波在一维声子晶体单晶体和被小的共振腔分开的双晶体中传播时发生的隧穿和共振隧穿现象的研究,观察到了声子晶体单晶体在带隙频率范围内发生的隧穿现象,而对于双晶体样品,在带隙频率范围内出现了很强的共振透射峰.共振发生时,实验测得的群时间很大,但是没有共振时,群速度却很快.
We investigated theoretically and experimentally the acoustic waves tunneling and resonant-tunneling through one- dimensional phononic crystals within the frequency gap. The phononic crystal consists of parallel and periodically arrayed plastic plates immersed in water. Acoustic tunneling was observed for this single crystal structure at frequencies inside the band gaps. By slightly increasing the separation of the two plates in the middle, a double-crystal structure forms, which allows acoustic waves to resonantly tunnel through it, with transmission peaks observed inside the band gaps. At resonance, the measured group time is large, while off resonance very fast group velocity is found.