1. Performance Optimization of a Three-Dimensional NanoSQUID Based on Niobium Tunnel Nanojunctions.
- Author
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Fretto, Matteo, Schmelz, Matthias, Vettoliere, Antonio, Zakosarenko, Vyacheslav, De Leo, Natascia, Stolz, Ronny, and Granata, Carmine
- Subjects
SUPERCONDUCTING quantum interference devices ,NANOELECTROMECHANICAL systems ,NIOBIUM ,TUNNEL junctions (Materials science) ,CAPACITANCE measurement ,CRITICAL current measurement ,MAGNETIC flux measurement - Abstract
We report results about an optimized three-dimensional nanoSQUID based on niobium tunnel nanojunctions having the loop suspended to reduce the parasitic capacitance. The SQUID loop has a size of 400 × 600 nm2 while the dimension of the square tunnel nanojunctions is 150 × 150 nm2 with a density of the critical current of about 35 × 103 A/cm2. The nanodevice has been characterized at liquid helium temperature; it has shown nonhysteretic current-voltage characteristics and smooth voltage- magnetic flux characteristics resulting in a very stable operation in a wide range of bias points. The spectral density of the magnetic flux noise in the white region, measured with a two-stage noise measurement setup, was as low as 300 nΦ0/Hz1/2 corresponding to a spin sensitivity of few Bohr magnetons for bandwidth unit. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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