Superconducting on-chip solenoid for Josephson junction characterization

Abstract

We report on the design and measurement of a superconducting solenoid integrated on chip with a Josephson junction fabricated in a multilayer 250 nm niobium process. The solenoid generates a current-tunable magnetic field parallel to the junction that allows us to fully suppress the dc Josephson current. The magnitude of the generated field is well approximated by a magnetostatic model, and the modulation of the critical current by the generated field agrees well with simulations for our specific junction geometry. This test circuit allows for the characterization of Josephson junctions in an applied magnetic field without requiring an externally supplied field.