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A three-wave mixing kinetic inductance traveling-wave amplifier with near quantum-limited noise performance



Maxime Malnou, Michael Vissers, Jordan Wheeler, Joe Aumentado, Johannes Hubmayr, Joel Ullom, Jiansong Gao


We present the theoretical model and experimental characterization of a microwave kinetic inductance traveling-wave amplifier (KIT), whose noise performance, measured by a shot noise thermometer, approaches the quantum limit. Biased with a dc current, this KIT operates in a three-wave mixing fashion, thereby reducing by several orders of magnitude the power of the microwave pump tone, compared to conventional four-wave mixing KIT devices. It is built in an artificial trans- mission line intrinsically matched to 50 Ω}, whose dispersion allows for a controlled amplification bandwidth. We experimentally measure 17.6 (+1.1, -1.4) dB of gain across a 2 GHz bandwidth, with an input 1 dB compression power of -63 dBm within that bandwidth, in qualitative agreement with theory. Using the KIT as the first amplifier in an amplification chain, we measure a system added noise of 0.61 ± 0.08 K between 3.5 and 5.5 GHz, at least three times better than the added noise of commercially available, high-power handling amplifiers. The KIT contribution to this added noise is estimated to be 0.19 ± 0.1 K, consistent with the quantum limit on amplifier added noise. This device is therefore suitable to read out large arrays of microwave kinetic inductance detectors or thousands of superconducting qubits.
Physical Review X


amplifier, traveling-wave, kinetic inductance, quantum limit, microwaves, dispersion engineering


Malnou, M. , Vissers, M. , Wheeler, J. , Aumentado, J. , Hubmayr, J. , Ullom, J. and Gao, J. (2021), A three-wave mixing kinetic inductance traveling-wave amplifier with near quantum-limited noise performance, Physical Review X (Accessed May 22, 2024)


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Created January 5, 2021, Updated May 26, 2023