An international collaboration led by researchers from CNR-SPIN (OXiNEMS project) realized a micro-mechanical resonators showing both high-Q-factor and high-Tc superconductivity by growing YBa2Cu3O7 on top of tensile-strained LaAlO3 micro-bridges. Such devices are of great interest towards the development of advanced sensors, superconducting physics, and quantum opto-mechanics.
Micro-mechanical resonators are building blocks of a variety of applications in basic science and consumer electronics and mainly based on well-established and reproducible silicon-based fabrication processes. State-of-the-art micro-mechanical resonators shows outstanding performances in term of mechanical Q-factor and sensitivity to external perturbations, but their integration with functional materials is still challenging. An alternative approach is directly fabricating MEMS based on compounds inherently showing non-trivial functional properties, such as transition metal oxides.
A collaboration between scientists from CNR-SPIN, Chalmers, and Genoa University demonstrated the potential of such approach by realizing a micro-mechanical resonator showing both high mechanical Q-factor and superconductivity at 77 K. This result was achieved by integrating a high-Tc superconductor YBa2Cu3O7 (YBCO) with high Q-factor micro-bridge resonators made of single-crystal LaAlO3 (LAO) thin films. Bare LAO resonators are tensile strained, with a stress of about 350 MPa, show a Q-factor above 200k, and have low roughness. YBCO overlayers were then grown ex-situ by pulse laser deposition on top of the suspended bridges. Final devices show zero resistance below 78 K and mechanical properties similar to those of bare LAO ones. These results open new possibilities towards the development of advanced transducers, such as bolometers or magnetic field detectors, as well as experiments in solid state physics, material science, and quantum opto-mechanics.
This research was developed in the framework of the OXiNEMS project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 828784.
N. Manca, A. Kalaboukhov, A. E. Plaza, L. Cichetto Jr., E. Wahlberg, E. Bellingeri, F. Bisio, F. Lombardi, D. Marré, L. Pellegrino, “Integration of High-Tc Superconductors with High-Q-Factor Oxide Mechanical Resonators” Adv. Funct. Mater. 2024, 2403155. https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202403155
