Proceedings of the First European Workshop on Low Temperature Electronics
J. Phys. IV France 04 (1994) C6-273-C6-278
Quasiparticle lifetimes and tunneling times in an SS'IS''S tunnel junction detectorA.A. Golubov1, E. P. Houwnan2, V.M. Krasnov1, J. G. Gijsbertsen2, J. Flokstra2, H. Rogalla2, J.B. le Grand3 and P.A.J. de Korte3
1 Institute of Solid State Physics, 142432 Chemogolovka, Moscow district, Russia
2 University of Twente, Department of Applied Physics, 7500 AE Enschede, The Netherlands
3 Laboratory for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
a tunnel junction detector with artificial trapping layers, S' and S", near the tunnel barrier can be described as an SS'IS"S structure. Gap reduction takes place in S due to the proximity effect with the S' (S") layer. Effective trapping, excitation and tunneling rates of the reduced gap region in the junction are calculated as a function of the operating temperature and junction bias voltage on the basis of a microscopic model of the proximity effect in the SS' sandwich. The calculations are done under the assumption that the thickness of the S' layer ds' is small compared to its coherence length ξs' and dirty limit conditions are fulfilled for both the S and S' metals. The limits of applicability of these approximations are discussed by calculating corrections to the space dependence of the order parameter in S and S' due to a) finite thickness ds' of the S' layer and b) for large mean free path ls,s' in the S and S' layers.
© EDP Sciences 1994