Design and Fabrication of Coupled NanoSQUIDs and NEMS

Two significant recent developments in measurement science involve nano-electromechanical systems (NEMS) resonators and nanoSQUIDs. Both show remarkable properties with important implications for the future of metrology and sensing at the nanoscale. In this paper we describe early work in bringing these two developments together into a combined system which will further enable novel and ultrasensitive measurements. The ability to operate SQUIDs at the nanoscale without compromising the near quantum-limited performance demonstrated at larger scale is shown through two different SQUID technologies. The first is based on superconductor-normal conductor-superconductor (SNS) Josephson junctions while the second uses nanoscale Dayem bridges. The noise performance of both is similar. We also present results on fabrication of NEMS resonators using focused ion beam (FIB) milling and show how such a resonator can be assembled in close coupling with a nanoSQUID.