Berlin 2015 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 21: Superconductivity: Poster Session
TT 21.4: Poster
Monday, March 16, 2015, 15:00–18:00, Poster B
Large Oscillations of the Magnetoresistance in Nanopatterned Thin Aluminum Films — •Christopher Espy1, Julian Braun1, Benjamin Lindner1, Omri Sharon2, Elke Scheer1, and Yosef Yeshurun2 — 1Universität Konstanz, Konstanz, Germany — 2Bar-Ilan University, Ramat Gan, Israel
With their experiments on thin superconducting cylinders Little and Parks demonstrated oscillations of the critical temperature with the flux threading the cylinder [1]. The periodicity of Φ0 = h/2e supported the picture of a correlated two-electron state, as predicted by BCS theory. However, theoretical studies predict a h/e periodicity in ring-shaped unconventional superconductors that can arise via various mechanisms, when the ring diameter becomes comparable to the coherence length, ξ0 [2, 3].
There is even speculation that this periodicity should be seen in rings made out of aluminum, a conventional s-wave superconductor, with diameters smaller than the coherence length, i.e. in the order of 1 µm [3]. Sochnikov et al. investigated this proposed periodicity in double network patterns of La1.84Sr0.16CuO4 but did not find the predicted periodicity [4]. We show first results of our experiments on such double networks of aluminum nano-rings.
[1] Little, W.A. and Parks, R. D., PRL 9, 9 (1962).
[2] Vakaryuk, V., PRL 101, 167002 (2008).
[3] Loder, F. et al., PRB 78, 174526 (2008).
[4] Socknikov, I. et al., Nat. Nanotech. 5, 516 (2010).