Near-degenerate quadrature-squeezed vacuum generation on a silicon-nitride chip

Understand

Squeezed states are a primary resource for continuous-variable (CV) quantum information processing.

• To implement CV protocols in a scalable and robust way, it is desirable to generate and manipulate squeezed states using an integrated photonics platform.
• In this Letter, we demonstrate the generation of quadrature-phase squeezed states in the radio-frequency carrier sideband using a small-footprint silicon-nitride microresonator with a dual-pumped four-wave-mixing process.
• We record a squeezed noise level of 1.34 dB ($\pm$0.16 dB) below the photocurrent shot noise, which corresponds to 3.09 dB ($\pm$0.49 dB) of quadrature squeezing on chip.