Pulse and Hold Strategy for Switching Current Measurements
2007 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 75, no 9, 094515- p.Article in journal (Refereed) Published
We investigate by theory and experiment, the Josephson junction switching current detector in an environment with frequency-dependent damping. Analysis of the circuit's phase space shows that a favorable topology for switching can be obtained with overdamped dynamics at high frequencies. A pulse-and-hold method is described, where a fast switch pulse brings the circuit close to an unstable point in the phase space when biased at the hold level. Experiments are performed on Cooper pair transistors and quantronium circuits, which are overdamped at high frequencies with an on-chip RC shunt. For 20 mu s switch pulses the switching process is well described by thermal equilibrium escape, based on a generalization of the Kramers formula to the case of frequency-dependent damping. A capacitor bias method is used to create very rapid, 25 ns switch pulses, where it is observed that the switching process is not governed by thermal equilibrium noise.
Place, publisher, year, edition, pages
2007. Vol. 75, no 9, 094515- p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:kth:diva-6275DOI: 10.1103/PhysRevB.75.094515ISI: 000245328500089ScopusID: 2-s2.0-34047190361OAI: oai:DiVA.org:kth-6275DiVA: diva2:10948
QC 201008122006-10-232006-10-232011-11-07Bibliographically approved