Shenzhen International Quantum Research Institute Makes significant progress in integrated quantum light source construction

TapTechNews August 24th news, the Shenzhen International Quantum Research Institute released a blog post yesterday (August 23rd), announcing that based on industrially mass-producible ultra-low-loss silicon nitride waveguides, important progress has been made in the construction of integrated quantum light sources.

Project Background

Quantum information provides a brand-new paradigm beyond classical methods for the generation, transmission, and processing of information, and is promoting a new round of transformation of the human information society.

Photons, due to their excellent quantum coherence, can effectively resist external environmental disturbances at room temperature, and therefore are one of the most important carriers of quantum information. Based on the regulation of photons, the quantum computational superiority has been verified, and an inter-city quantum communication network has been established.

However, so far, large-scale photonic quantum information processing systems are all based on free-space optics or fiber optics, and their scalability still faces significant challenges.

In recent years, photonic quantum information processing based on optical chips has also gradually come into people's vision, and most of the related work is based on the most mainstream commercial silicon photonics platform at present. However, the loss of silicon waveguide over 1 dB/cm severely limits its ability to carry out photon-level experiments.

Project Introduction

The research team of Liu Junqiu from the Shenzhen International Quantum Research Institute uses ultra-high-quality factor microcavities, the linewidth of the photon pairs generated by this integrated light source reaches the atomic transition line magnitude for the first time, and its brightness is the best record of the silicon-based integrated optical platform so far.

The team mainly introduces silicon nitride materials, providing an excellent solution. Silicon nitride has many extremely excellent optical characteristics, including the optical transparent range from ultraviolet to mid-infrared, no two-photon absorption at the communication wavelength, and appropriate Kerr nonlinearity, etc.

The processing of silicon nitride optical chips can be fully compatible with the current standard CMOS silicon chip process and achieves a linear loss as low as 0.01 decibel per centimeter.

Through intracavity spontaneous four-wave mixing, the research team prepared photon pairs with a linewidth as low as 25.9 MHz, which is the first time that the chip-integrated narrow-linewidth quantum light source reaches the atomic transition line magnitude.

TapTechNews attaches the reference address