Surface-Wave Coupling to Single Phononic Subwavelength Resonators

Interaction of a micromechanical resonator with a supporting surface is usually seen as an intense source of loss, and thus detrimental. However, in analogy to plasmonics, one can imagine using phononic chains to carry elastic energy in subwavelength structures. The authors show that resonator-surface coupling can be used to manipulate mechanical vibrations, reporting strong confinement of elastic energy in cylindrical pillars with dimensions of 1/10 the excitation wavelength or less. Individual resonators in ensembles can be addressed independently as a function of driving frequency, opening the door to coherent, high-frequency distribution and confinement of microscale elastic waves.