Reflection-enhanced gain in traveling-wave parametric amplifiers
Journal article, 2023
The operating principle of traveling-wave parametric amplifiers is typically understood in terms of the standard coupled mode theory, which describes the evolution of forward propagating waves without any reflections, i.e., for perfect impedance matching. However, in practice, superconducting microwave amplifiers are unmatched nonlinear finite-length devices, where the reflecting waves undergo complex parametric processes, not described by the standard coupled mode theory. Here, we present an analytical solution for the TWPA gain, which includes the interaction of reflected waves. These reflections result in corrections to the well-known results of the standard coupled mode theory, which are obtained for both three-wave and four-wave mixing processes. Due to these reflections, the gain is enhanced and unwanted nonlinear phase modulations are suppressed. Predictions of the model are experimentally demonstrated on two types of unmatched TWPA, based on coplanar waveguides with a central wire consisting of (i) a high kinetic inductance superconductor, and (ii) an array of 2000 Josephson junctions.
Author
S. Kern
Comenius University in Bratislava
P. Neilinger
Comenius University in Bratislava
Slovak Academy of Sciences
E. Il'Ichev
Leibniz Association
A. Sultanov
Aalto University
M. Schmelz
Leibniz Association
S. Linzen
Leibniz Association
J. Kunert
Leibniz Association
G. Oelsner
Leibniz Association
R. Stolz
Leibniz Association
Andrey Danilov
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Sumedh Mahashabde
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
Aditya Jayaraman
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
V. Antonov
Royal Holloway University of London
Sergey Kubatkin
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
M. Grajcar
Comenius University in Bratislava
Slovak Academy of Sciences
Physical Review B
24699950 (ISSN) 24699969 (eISSN)
Vol. 107 17 174520Mikrovågsförstärkare med kvantbegränsad prestanda
Swedish Research Council (VR) (2016-04828), 2017-01-01 -- 2020-12-31.
Wallenberg Centre for Quantum Technology (WACQT)
Knut and Alice Wallenberg Foundation (KAW 2017.0449, KAW2021.0009, KAW2022.0006), 2018-01-01 -- 2030-03-31.
European Microkelvin Platform (EMP)
European Commission (EC) (EC/H2020/824109), 2019-01-01 -- 2022-12-31.
Subject Categories (SSIF 2011)
Telecommunications
Other Physics Topics
Condensed Matter Physics
DOI
10.1103/PhysRevB.107.174520