%0 Journal Article
%T Engineering physics of superconducting hot-electron bolometer mixers
%A Klapwijk, T. M.
%A Semenov, A. V.
%J IEEE Trans. THz Sci. Technol.
%D 2017
%V 7
%N 6
%@ 2156-342X
%F Klapwijk+Semenov2017
%O exported from refbase (https://db.rplab.ru/refbase/show.php?record=1292), last updated on Sun, 09 May 2021 23:51:58 -0500
%X Superconducting hot-electron bolometers are presently the best performing mixing devices for the frequency range beyond 1.2 THz, where good-quality superconductor-insulator-superconductor devices do not exist. Their physical appearance is very simple: an antenna consisting of a normal metal, sometimes a normal-metal-superconductor bilayer, connected to a thin film of a narrow short superconductor with a high resistivity in the normal state. The device is brought into an optimal operating regime by applying a dc current and a certain amount of local-oscillator power. Despite this technological simplicity, its operation has found to be controlled by many different aspects of superconductivity, all occurring simultaneously. A core ingredient is the understanding that there are two sources of resistance in a superconductor: a charge-conversion resistance occurring at a normal-metal-superconductor interface and a resistance due to time-dependent changes of the superconducting phase. The latter is responsible for the actual mixing process in a nonuniform superconducting environment set up by the bias conditions and the geometry. The present understanding indicates that further improvement needs to be found in the use of other materials with a faster energy relaxation rate. Meanwhile, several empirical parameters have become physically meaningful indicators of the devices, which will facilitate the technological developments.
%K HEB mixers
%R 10.1109/TTHZ.2017.2758267
%U http://ieeexplore.ieee.org/document/8086223/
%U https://doi.org/10.1109/TTHZ.2017.2758267
%P 627-648