Acoustic confinement phenomena in oxide multifunctional nanophononic devices

A. E. BRUCHHAUSEN; N. D. LANZILLOTTI-KIMURA; B. JUSSERAND ; A. SOUKIASSIAN; L. XIE; X. Q. PAN; T. DEKORSY; D. G. SCHLOM; A. FAINSTEIN

Physical Review Materials

APS

Año: 2018

2475-9953

Engineering of phononic resonances in ferroelectric structures is a new knob to realize novel mul-tifunctional devices. Here we show the possibility of predictively designing and fabricating phononicnanoresonators utilizing combinations of MBE-grown insulating (BaTiO 3 , SrTiO 3 ) and metallic(SrRuO 3 ) oxides. We experimentally demonstrate the confinement of acoustic waves in the 100GHz frequency range in a phonon nanocavity, where the time and spatial beatings result from thecoupling of two different hybrid nanocavities forming an acoustic molecule. Additionally, the directmeasurement of Bloch-like oscillations of acoustic phonons is observed in a system formed by 10coupled resonators. Utilizing coherent phonon generation techniques we study phonon dynamicsdirectly in the time-domain. The metallic SrRuO 3 layer introduces a local phonon generator andtransducer that allows for the spatial, spectral and time-domain monitoring of the complex gen-erated waves. Our results introduce ferroelectric cavity systems as a new realm for the study ofcomplex wave localization phenomena at the nanoscale. These systems can be successfully designedand conceived using state of the art growth techniques that combine perovskite oxides possessingmultifunctional properties