1.2 GHz Balanced Homodyne Detector for Continuous-Variable Quantum Information Technology

TL;DR

This paper presents a novel 1.2 GHz bandwidth balanced homodyne detector designed with integrated circuit technology, significantly enhancing quantum information processing capabilities such as quantum key distribution and random number generation.

Contribution

The paper introduces a wideband BHD with high quantum-to-classical noise ratio, linear gain, and high common mode rejection, enabling faster quantum communication and random number generation.

Findings

Bandwidth up to 1.2 GHz achieved

Quantum to classical noise ratio around 18 dB

Quantum random number generation rate up to 6.53 Gbps

Abstract

Balanced homodyne detector (BHD) that can measure the field quadratures of coherent states has been widely used in a range of quantum information technologies. Generally, the BHD tends to suffer from narrow bands and an expanding bandwidth behavior usually traps into a compromise with the gain, electronic noise, and quantum to classical noise ratio, etc. In this paper, we design and construct a wideband BHD based on radio frequency and integrated circuit technology. Our BHD shows bandwidth behavior up to 1.2 GHz and its quantum to classical noise ratio is around 18 dB. Simultaneously, the BHD has a linear performance with a gain of 4.86k and its common mode rejection ratio has also been tested as 57.9 dB. With this BHD, the secret key rate of continuous-variable quantum key distribution system has a potential to achieve 66.55 Mbps and 2.87 Mbps respectively at the transmission distance of 10 km and 45 km. Besides, with this BHD, the generation rate of quantum random number generator could reach up to 6.53Gbps.