Toward the near-quantum-limited multiplexed readout of hundreds of resonators with a KI-TWPA

As the number of qubits in quantum computers continues to increase, their readout architecture will face the same technical challenge as arrays of transition-edge sensors and microwave kinetic inductance detectors: namely, what is a scalable solution for the quantum-limited readout of hundreds and thousands of frequency-multiplexed resonators? For both qubit and sensor applications, the cooling power required to brute-force scale the existing cryogenic semiconductor amplifier technology is a major obstacle. In this context, traveling-wave parametric amplifiers (TWPAs) have emerged as a more power-efficient solution [1], with nearly quantum-limited noise performance. In this talk, I will discuss the design and characterization of highly scalable readout architectures leveraging TWPAs, and will present our efforts to measure an array of 64 nonlinear resonators with a kinetic-inductance TWPA, whose added noise approaches the quantum limit.

 

[1]: arXiv: 2110.08142 (2021)