  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. We also show that it is
critical to account for the nonlinear behavior of the pump fields to properly
predict the squeezing that can be generated in this system. This technology
represents a significant step toward creating and manipulating large-scale CV
cluster states that can be used for quantum information applications including
universal quantum computing.
