Conventional proximity effect in bilayers of superconducting underdoped $La_{1.88}Sr_{0.12}CuO_4$ islands coated with non superconducting overdoped $La_{1.65}Sr_{0.35}CuO_4$

G. Koren; O. Millo

paper

Conventional proximity effect in bilayers of superconducting underdoped $L a_{1.88} S r_{0.12} C u O_{4}$ islands coated with non superconducting overdoped $L a_{1.65} S r_{0.35} C u O_{4}$

arXiv:0904.1928

Abstract

Following a recent study by our group in which a large $T_{c}$ enhancement was reported in bilayers of the non-superconducting $L a_{1.65} S r_{0.35} C u O_{4}$ and superconducting $L a_{1.88} S r_{0.12} C u O_{4}$ films [Phys. Rev. Lett. \textbf{101}, 057005 (2008)], we checked if a similar effect occurs when superconducting $L a_{1.88} S r_{0.12} C u O_{4}$ islands are coated with a continuous layer of the non superconducting $L a_{1.65} S r_{0.35} C u O_{4}$ . We found that no such phenomenon is observed. The bare superconducting islands film behaves as an insulator where transport occurs via hopping or tunneling between islands, but exhibits a weak signature of localized superconductivity at $\sim$ 18 K. When over coated with a $L a_{1.65} S r_{0.35} C u O_{4}$ film, it becomes superconducting with a $T_{c}$ onset of 16.6 K, which is less than that of a thick $L a_{1.88} S r_{0.12} C u O_{4}$ film (25.7 K). We therefore conclude that the lower $T_{c}$ in the bilayer is due to a conventional proximity effect.

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Conventional proximity effect in bilayers of superconducting underdoped La1.88​Sr0.12​CuO4​ islands coated with non superconducting overdoped La1.65​Sr0.35​CuO4​

Abstract

Conventional proximity effect in bilayers of superconducting underdoped $L a_{1.88} S r_{0.12} C u O_{4}$ islands coated with non superconducting overdoped $L a_{1.65} S r_{0.35} C u O_{4}$