Fabrication and Properties of Josephson Junction Cantilevers for Terahertz Applications

authored by

Ilya Elenskiy, Marco Tollkuhn, Denis Kajevic, Michael Martens, Benedikt Hampel, Meinhard Schilling

Abstract

Josephson cantilevers are employed to measure the three-dimensional radiation distribution at microwave frequencies and up to the terahertz regime. Epitaxial YBa₂Cu₃O₇ Josephson junctions with high I_cR_n products are required at these frequencies. The commonly used epitaxial Josephson junctions on LaAlO₃ bicrystal substrates fulfill these requirements but exhibit significant variance in their electronic properties. In addition, the substrate losses have to be minimized and, therefore, only substrate materials with low relative permittivity _r and loss tangent tan δ in the microwave regime are suitable. The fabrication is realized by optimized pulsed laser deposition of YBa₂Cu₃O₇. The separated devices are automatically characterized including the electric I-V curves and temperature dependence. In addition, the microwave properties are determined in our terahertz microscope at 762 GHz with a far infrared laser system and low-noise measurement electronics. The Josephson cantilevers are used to measure the spatial power distribution of the laser beam by differential resistance analysis and by Hilbert transform of the first Shapiro step. The latter approach shows a good agreement with the expected beam profile.

External Organisation(s)

Technische Universität Braunschweig

Type

Article

Journal

IEEE Transactions on Applied Superconductivity

Volume

29

ISSN

1051-8223

Publication date

08.2019

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials, Condensed Matter Physics, Electrical and Electronic Engineering

Electronic version(s)

https://doi.org/10.1109/tasc.2019.2900217 (Access: Closed)