Traveling-Wave Parametric Amplifier Based on a Chain of Coupled Asymmetric SQUIDs

Abstract

A traveling wave parametric amplifier (TWPA) composed of a transmission line made up of a chain of coupled asymmetric superconducting quantum interference devices (SQUIDs) is proposed. The unique nature of this transmission line is that its nonlinearity can be tuned with an external magnetic flux and can even change sign. This feature of the transmission line can be used to perform phase matching in a degenerate four-wave mixing process which can be utilized for parametric amplification of a weak signal in the presence of a strong pump. Numerical simulations of the TWPA design have shown that with tuning, phase matching can be achieved and an exponential gain as a function of the transmission line length can be realized. The flexibility of the proposed design can realize: compact TWPAs with less than 211 unit cells, signal gains greater than 20 dB, 3 dB bandwidth greater than 5.4 GHz, and saturation powers up to -98 dBm. This amplifier design is well suited for multiplexed readout of quantum circuits or astronomical detectors in a compact configuration which can foster on-chip implementations.

Optimizing the Nonlinearity and Dissipation of a SNAIL Parametric Amplifier for Dynamic Range

“…More broadly, the optimizations performed in this work for higher dynamic range do not conflict with recent approaches for enhanced dynamic bandwidth via impedance engineering [18,31], nor with approaches for directional amplification [32][33][34][35][36][37]. The reduction of Kerr and the use of arrays of nonlinear elements should also increase the dynamic range of traveling wave amplifiers [13,[38][39][40][41][42].…”

Squeezing and quantum state engineering with Josephson travelling wave amplifiers

“…One can therefore approximate the device with a continuum description (formally taking the unit cell distance, a, to zero). We furthermore assume that the JTWPA is coupled to identical, semi-infinite and impedance matched transmission lines to the left and the right, as illustrated in placed by SQUIDs have recently been discussed [52,53]. We do not consider such modifications here, but the general approach we develop below can be used to formulate a quantum theory also in these cases.…”

Superconducting Josephson-Based Metamaterials for Quantum-Limited Parametric Amplification: A Review

“…It can be implemented in multiple ways [25], by the way, it has to be noticed that this method requires an increase of design complexity, lower tolerances on the constructing parameters and longer propagation lengths (2 cm -1 m). Another option to solve the mismatch problem was suggested by Bell and Samlov [26], who proposed a self-phase matching transmission line embedding a series of asymmetric superconducting quantum interference devices (SQUIDs). The remarkable feature of this design is that it does not need any resonant circuit to achieve phase matching.…”