Quadrature squeezing in a nanophotonic microresonator

Diego Martín-Cano, Harald R. Haakh, Mario Agio

Alexander E. Ulanov, Bastian Ruhnke, Thibault Wildi +1 more

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.

Ruiqin Fan, Hong-guang Yang, Zhi-Ming Bai

Alexander E. Ulanov, Bastian Ruhnke, Thibault Wildi +1 more

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.

Chan U Lei, Aaron Weinstein, Junho Suh +2 more

Yichen Shen, Ping‐Yen Hsieh, Sashank Kaushik Sridhar +4 more

We report the highest level of squeezing directly detected from a microresonator, 3.7 dB (10.7 dB inferred). We use Si3N4 nanophotonic microrings operated in the continuous-wave regime and observe stable squeezing with minimal excess classical noise.