Quadrature squeezing in a nanophotonic microresonator

TL;DR

This paper demonstrates on-chip quadrature squeezing in a silicon-nitride microresonator, overcoming parasitic nonlinear effects, and achieving significant squeezing levels for quantum photonic applications.

Contribution

It introduces a scalable, low-loss photonic chip platform with tailored nano-corrugation to suppress parasitic nonlinear processes, enabling effective quadrature squeezing.

Findings

Achieved 7.8 dB of on-chip squeezing.

Used a nano-corrugated microresonator to suppress parasitic nonlinearities.

Demonstrated potential for scalable quantum photonic technologies.

Abstract

Squeezed states of light are essential for emerging quantum technology in metrology and information processing. Chip-integrated photonics offers a route to scalable and efficient squeezed light generation, however, parasitic nonlinear processes and optical losses remain significant challenges. Here, we demonstrate single-mode quadrature squeezing in a photonic crystal microresonator via degenerate dual-pump spontaneous four-wave mixing. Implemented in a scalable, low-loss silicon-nitride photonic-chip platform, the microresonator features a tailored nano-corrugation that modifies its resonances to suppress parasitic nonlinear processes. In this way, we achieve an estimated 7.8 dB of on-chip squeezing in the bus waveguide, with potential for further improvement. These results open a promising pathway toward integrated squeezed light sources for quantum-enhanced interferometry, Gaussian boson sampling, coherent Ising machines, and universal quantum computing.