Quantum acoustics

Researchers: Matteo Fisicaro, Thomas Steenbergen


Surface acoustic waves (SAWs) are mechanical waves that travel on the surface of a material and can be controlled down to the quantum level. They are commonly excited and detected using interdigital transducers (IDTs) consisting of two interleaved comb-shaped metal electrodes on a piezoelectric substrate. We show here the nanofabrication of a GHz IDT device on a GaAs substrate, and its characterization, both electrically and optically by means of interferometric measurements. The optical measurement of the generated SAWs is the first step towards integrating the IDT device in our custom built open-access optical microcavity which is compatible with a closed-cycle cryostat. This novel platform can be used in the future for quantum acoustics experiments, where in principle even a single SAW phonon can be detected via the quantum-confined Stark shift it induces in a single quantum dot.