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, lattice termination at the material surface, or charge transfer at the interface of different materials may induce piezoelectricity near those surfaces and interfaces, even if though materials have centrosymmetric lattice structures. Here, we conduct an experimental study of the interface piezoelectric effect in silicon using surface acoustic waves. By performing microwave transmission measurement and analyzing the time-domain response, we can isolate this effect from the noisy environment and understand its strength and material/geometry dependence. As the next step, we will couple the surface acoustic wave with superconducting qubits via the interface piezoelectricity to study how this electromechanical response affects the qubits performance. A thorough understanding of the interface 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 in both traditional and quantum applications.
Project is currently funded by: Federal