@article{098d1ab804c04b2ba30577a8dcfc6ddf,
title = "MgB2/MgO/MgB2 josephson junctions for high-speed circuits",
abstract = "MgB2/MgO/MgB2 sandwich-type Josephson junctions have been fabricated using MgB2 films grown by hybrid physical-chemical vapor deposition (HPCVD). The MgO barrier and the insulating layer between wiring layers were made by RF magnetron sputtering. The junctions exhibit non-vanishing Jc up to 40 K, the Tc of MgB 2·MgB2 wiring is achieved without significantly changing the junction properties. The fabrication and properties of the junctions are described in detail. The I-V curves of the junctions are hysteretic at temperatures below 25 K and are RSJ-like above 25 K. Multiple Andreev reflection was observed, manifested by subgap peaks in the dI/dV-V curves and in good agreement with the theory. The Jc spread (1 σ)of 10 junctions on one chip is better than 10%, which is likely due to the defects inside the MgO barrier as identified by transmission electron microscopy. Superconducting circuits made of these junctions may be expected to work at frequencies up to 1 THz or at temperatures over 20 K.",
author = "Ke Chen and Zhuang, {C. G.} and Qi Li and X. Weng and Redwing, {J. M.} and Y. Zhu and Voyles, {P. M.} and Xi, {X. X.}",
note = "Funding Information: Manuscript received August 03, 2010; accepted November 14, 2010. Date of publication December 30, 2010; date of current version May 27, 2011. This work was supported in part by the US Office of Naval Research under Grant N00014-10-1-0164 and by the US Department of Energy under Grant DE-FG02-08ER46531. K. Chen, C. G. Zhuang, and X. X. Xi are with Department of Physics, Temple University, Philadelphia, PA 19122, USA (e-mail: kchen@temple.edu). Q. Li is with Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA. X. Weng and J. M. Redwing are with Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA. Y. Zhu and P. M. Voyles are with Department of Materials Science and Engineering, University of Wisconsin, Madison, WI 53706, USA. Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TASC.2010.2093853 Funding Information: ACKNOWLEDGMENT The authors thank John Rowell, Alan Kleinsasser, Bob Burhman, Bob Dynes, Nate Newman, and Ruggero Vaglio for helpful discussions. This publication was supported by the Pennsylvania State University Materials Research Institute Nanofabrication Lab and the National Science Foundation Cooperative Agreement 0335765, National Nanotechnology Infrastructure Network, with Cornell University.",
year = "2011",
month = jun,
doi = "10.1109/TASC.2010.2093853",
language = "English (US)",
volume = "21",
pages = "115--118",
journal = "IEEE Transactions on Applied Superconductivity",
issn = "1051-8223",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "3 PART 1",
}