A method for determining dissipative effects in superconductive devices

S. V. Aksenov, M. S. Shustin, I. S. Burmistrov

Anedio Ranfagni, Gian Paolo Pazzi, Ilaria Cacciari

A stochastic model, which demonstrated to be capable of determining dissipative effects in the microwave circuits loading superconducting devices, is found to be suitable also for analyzing near-field microwave propagation when the wave attenuation is interpreted as a dissipative effect. An alternative approach to the problem is offered by Feynman’s transition elements.

Eliot Kapit

Covelli, Vito, L. Piccirillo

We describe some characterization methods for the determination of qualitative parameters of superconducting Josephson effect devices. We propose the introduction of a new method to characterize the junctions at the ambient temperature. This method accounts the effects of the single electron tunneling. We also used SEM techniques for technological analysis of the devices.

T. M. Klapwijk, D. R. Heslinga, Wim M. van Huffelen

Daniela Mugnai, Anedio Ranfagni, Ilaria Cacciari

The results relative to macroscopic quantum tunneling rate, out of the metastable state of Josephson junctions, are examined in view of determining the effect of dissipation. We adopt a simple criterion in accordance to which the effect of dissipation can be evaluated by analyzing the shortening of the semiclassical traversal time of the barrier. In almost all the considered cases, especially those with relatively large capacitance values, the relative time shortening turns out to be about 20% and with a corresponding quality factor Q ≃ 5.5. However, beyond the specific cases here considered, still in the regime of moderate dissipation, the method is applicable also to different situations with different values of the quality factor. The method allows, within the error limits, for a reliable determination of the load resistance RL, the less accessible quantity in the framework of the resistively and capacitively shunted junction model, provided that the characteristics of the junction (intrinsic capacitance, critical current, and the ratio of the bias current to the critical one) are known with sufficient accuracy.