Piezoelectricity is the ability of certain materials to generate an electric polarization in response to applied mechanical stress or generate a mechanical deformation in response to applied voltage. It has broad applications where transduction between electrical and mechanical energy is required. It may also play a negative role and affect the performance of electronic devices. An example is the piezoelectric loss in superconducting qubits. While bulk piezoelectricity usually only exists in materials without inversion symmetry, theoretical calculation predicted that the piezoelectric effect may exist at the surface of inversion-symmetric materials. These materials include silicon and sapphire, which are widely used in semiconductor and quantum technologies. Here, we propose an experiment to probe the surface piezoelectric effect in these materials using the surface acoustic waves. By performing time-domain microwave measurement, we will be able to isolate this effect from the noisy environment and understand its strength and material/geometry dependence. A thorough understanding of the surface piezoelectricity will provide important guidance to improve the performance of superconducting qubits and semiconductor sensors. Furthermore, this effect may be utilized to achieve piezoelectric transduction without introducing bulk piezoelectric materials to the system.
Project is currently funded by: Federal