A Method to Probe the Interfaces in La 2− x Sr x CuO 4 -LaSrAlO 4 -La 2− x Sr x CuO 4 Trilayer Junctions

Condensed Matter

article

Xiaotao Xu¹  Xi He¹  Anthony T. Bollinger¹  Myung-Geun Han¹  Yimei Zhu¹  Xiaoyan Shi²  Ivan Božović¹ 

[1] Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory;Department of Physics, The University of Texas at Dallas;Department of Chemistry, Yale University;Energy Sciences Institute, Yale University

关键词: superconductivity;    cuprates;    oxide molecular beam epitaxy;    superlattice;   

DOI  :  10.3390/condmat8010021

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

C-axis trilayer cuprate Josephson junctions are essential for basic science and digital circuit applications of high-temperature superconductors. We present a method for probing the interface perfection in La2−xSrxCuO4 (LSCO)-LaSrAlO4 (LSAO)-La2−xSrxCuO4 trilayer junctions. A series of LSCO-LSAO superlattices with atomically smooth surfaces and sharp interfaces were grown by the atomic-layer-by-layer molecular beam epitaxy (ALL-MBE) technique. We have systematically varied the thickness of LSCO and LSAO layers with monolayer precision. By studying the mutual inductance and electrical transport in these superlattices, we detect the non-superconducting (“dead”) layers at the interfaces and quantify their thicknesses. Our results indicate that two optimally doped LSCO monolayers just above and below the one monolayer LSAO barrier are no longer superconducting, rendering the actual barrier thickness of five monolayers. Next, we have shown that introducing a protective highly-overdoped LSCO layer reduces the thickness of dead layers by one or two monolayers.

【 授权许可】

CC BY