Low-noise kinetic inductance traveling-wave amplifier using three-wave mixing

TL;DR

This paper reports the development of a low-noise, wide-bandwidth superconducting traveling-wave amplifier using three-wave mixing, achieving near-quantum-limited noise performance and high gain for quantum applications.

Contribution

The paper introduces a novel NbTiN-based kinetic inductance traveling-wave amplifier utilizing three-wave mixing, with significantly lower pump power and broader bandwidth than previous four-wave mixing devices.

Findings

Gain exceeds 15 dB across 4-8 GHz

Noise approaches the quantum limit with less than 1 photon excess

Operates at lower RF pump power and frequencies compared to four-wave mixing amplifiers

Abstract

We have fabricated a wide-bandwidth, high dynamic range, low-noise cryogenic amplifier based on a superconducting kinetic inductance traveling-wave device. The device was made from NbTiN and consisted of a long, coplanar waveguide on a silicon chip. By adding a DC current and an RF pump tone we are able to generate parametric amplification using three-wave mixing. The devices exhibit gain of more than 15 dB across an instantaneous bandwidth from 4 to 8 GHz. The total usable gain bandwidth, including both sides of the signal-idler gain region, is more than 6 GHz. The noise referred to the input of the devices approaches the quantum limit, with less than 1 photon excess noise. Compared to similarly constructed four-wave mixing amplifiers, these devices operate with the RF pump at $\sim$20 dB lower power and at frequencies far from the signal. This will permit easier integration into large scale qubit and detector applications.