Nb/a-Si/Nb Josephson junctions for high-density superconducting circuits
Abstract
We present electrical characterization data of sputtered Nb/a-Si/Nb Josephson junctions (JJs) for high-speed and high-density superconducting circuits. Junctions were studied with critical current densities (Jc) ranging from 0.01 to 3 mA/μm2 at 4 K. For junctions deposited at room temperature and processed to a maximum temperature of 150 °C, the dependence of Jc on barrier thickness d is exponential, Jc∝exp (−d/d0), with d0 constant over the entire range of Jc values studied. Junctions were annealed at temperatures up to 300 °C to study changes in their electrical properties and possible compatibility with high temperature fabrication processes. Current–voltage characteristics, critical current uniformity, critical current modulation with in-plane magnetic field, and sub-gap resistance behavior of these junctions were measured at 4 K and demonstrate that the junction properties do not degrade with annealing. These data indicate that Nb/a-Si/Nb JJs are a potential candidate for higher speed and higher density superconducting circuits.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 01, 2023
- Source ID
- 10.1063/5.0148250
Entities
People
- Adam Sirois
- D. Olaya
- John Biesecker
- Manuel Castellanos-Beltran
- Paul D Dresselhaus
- Peter F Hopkins
- Samuel P Benz
Organizations
- Intelligence Advanced Research Projects Activity
- National Institute of Standards and Technology
- University of Colorado