Page: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
This report raises many questions and gives few answers. For example, why do the threshold voltage histograms sometimes have multiple peaks? And why does the distance between those peaks change with magnetic field? And does this distance depend periodically on the field? The peaks in the Vt vs. B and R0 vs. B diagrams are most likely due to second loop sizes in the array. But how can this give rise to a sudden Hall voltage? Future experimental and theoretical work will answer these questions.
The complex frequency and starting voltage dependence of the threshold voltage can probably be explained by the relaxation of excess charges in the array. Future experiments could try to measure the relaxation time and which parameters that affect this time.
[1] B.D. Josephson, Phys. Lett. 1, 251 (1962)
[2] D.A. Averin and K.K. Likharev, in Mesoscopic Phenomena in Solids, edited by
B.L. Altshuler, P.A. Lee and R.A. Webb, p. 173 (North-Holland, Amsterdam, 1991)
[3] T.C. Halsey, Phys. Rev. B 31, 5728 (1985)
[4] S. Teitel and C. Jayaprakash, Phys. Rev. Lett. 51, 1999 (1983)
[5] C.J. Lobb, F.W. Abraham and M. Tinkham, Phys. Rev. B 27, 150 (1983)
[6] C.D. Chen, P. Delsing, D.B. Haviland, Y. Harada and T. Claeson, Phys. Rev. B
51, 15645 (1995)
[7] H.S.J. van der Zant, H.A. Rijken and J.E. Mooij, J. Low Temp. Phys. 79, 289
(1990)
[8] G.J. Dolan, Appl. Phys. Lett. 31, 337 (1977)
[9] P. Delsing, C.D. Chen, D.B. Haviland, Y. Harada and T. Claeson, Phys. Rev. B
50, 3959 (1994)
[10] N.S. Bakharov, G.S. Kazacha, K.K. Likharev and S.I. Serdyukova, Physica B
173, 319 (1991)
[11] Unpublished measurements on 1D arrays of squids by D.B. Haviland.
First of all I would like to thank ChiiDong Chen, who has taught me how to fabricate and measure these arrays and patiently answered all my questions. This is his work as much as mine.
My supervisors, Per Delsing and David Haviland, have helped me a lot while I was writing this thesis and tried to get some sense out of the measured data.
Several other people have helped me with this and that and have been good friends: Peter Wahlgren (thanks for the Dolan bridge picture!), Joakim Pettersson, Magnus Persson, Torsten Henning.
And thanks to Inger Ekvall for the dance.
18
My homepage.