A Monolithic Thin Film DC-SQUID

S. Menkel, C. Aßmann, G.S. Krivoy +1 more

Kyoko Kojima, Shigetoshi Nara, Koichi Hamanaka

A thin-film dc superconducting quantum interference device (SQUID) consisting of quasiparticle-injected superconducting weak links was fabricated and successfully operated. This SQUID was made on a silicon substrate and it consists of a ∼100-nm-thick lead alloy with two injector junctions. The characteristics of this dc SQUID are controllable by varying the injecting rate of quasiparticles; therefore, it can be operated at arbitrary temperatures below the transition temperature of the superconducting material.

Horst Rogalla, Bernd R. David, J. Rühl

Small area planar Nb3Ge dc-SQUIDs with wide operating temperature range were obtained using thin (40 nm) Nb3Ge films with high transition temperature Tc and small critical current per unit length. The SQUIDS were fabricated using electron beam lithography and reactive ion etching. SQUID operation was observed in the temperature range from 10 to 18.4 K with a best modulation depth of 11%.

Sergio Nicola Erne, H. Koch, Holger M. Luther

Sebastian Kempf

Jørn Bindslev Hansen

We have investigated phase-locking and voltage-locking in systems consisting of two planar dc-SQUIDs* located close together in the same superconducting film. The locking strength was found to be strongly dependent on the fluxoid state of both SQUIDs. We present a simple model for the inductive coupling between such two dc-SQUIDs and compare the prediction of the model with the experimental results.