A near-quantum limited Kinetic-Inductance Traveling-Wave Parametric Amplifier (KI-TWPA) using four-wave mixing

Kinetic inductance traveling-wave parametric amplifiers (KI-TWPA) offer wide instantaneous bandwidth, quantum noise limited performance, and high dynamic range, making them suitable for use in the readout of cryogenic detectors and superconducting qubits and a variety of applications in quantum sensing. This work discusses the design, fabrication, and measurements of a four-wave mixing microstrip KI-TWPA operating in the 4 - 8 GHz band. This frequency band is commonly used to read out cryogenic detectors such as microwave kinetic inductance detectors (MKIDs) and superconducting Josephson junction-based qubits. We report a measured gain of over 15 dB using four-wave mixing with a high dynamic range in the 4 - 8 GHz band. We also show the tunability of bandwidth by setting the pump-tone condition. Using a Y-factor method, we measure a near quantum limit KI-TWPA added noise in the 4 - 8 GHz band.