The Generation and Detection of Squeezed Microwave Photons Realized using Traveling-Wave Parametric Amplifiers

Abstract

Squeezing the electromagnetic vacuum is an essential metrological technique used to reduce quantum noise in applications spanning gravitational wave detection, biological microscopy, and quantum information science. In circuit quantum electrodynamics, Josephson parametric amplifiers play a crucial role in quantum-limited amplification and squeezed microwave generation. In this thesis, we develop a dual-pump, broadband Josephson traveling-wave parametric amplifier (JTWPA) to demonstrate non-degenerate four-wave mixing using a dual-dispersion-engineered JTWPA and investigate its squeezing performance. Furthermore, the thesis extends the existing JTWPA design to a lower frequency spectrum in the hundreds of MHz regime and demonstrates broadband parametric amplification with a large gain. Capable of multiplexed readout and improved signal-to-noise ratio, the new JTWPA can be utilized in a wide range of applications in condensed matter and astrophysics.