A high-resolution Josephson sampler using a single fluxoid is fabricated. The sampling pulse generator comprised a two-junction interferometer (dc-SQUID) with a damping resistance resistivity coupled to a single junction as the sampling gate to reduce a turn-on delay. An ultra-fast sampling pulse was generated at a vortex-to-vortex transition in this sampler. The fabricated sampler had less than a 5ps time resolution and about a 5 mu A current sensitivity. The dynamic waveform associated with two kinds of transition was observed by the use of this sampler: a vortex-to-vortex transitons and a vortex-to-vortex transition. The results show that the pulse corresponding to a single fluxoid has a nearly constant pulse height that is independent of the bias current and that setting the bias current near the critical point results in the long rise time of a dc-SQUID.
|Title of host publication||Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes|
|Number of pages||7|
|Publication status||Published - 1987 Jan|
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