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Self-Testing Quantum Randomness Expansion on an Integrated Photonic Chip

Gong Zhang1,2,*, Ignatius William Primaatmaja1,3, Yue Chen1, Si Qi Ng1,4, Hong Jie Ng1,3, Marco Pistoia5,6,7, Xiao Gong1, Koon Tong Goh3, Chao Wang1 et al.

Charles Lim1,†

  • 1Department of Electrical & Computer Engineering, National University of Singapore, Singapore
  • 2State Key Laboratory of Extreme Photonics and Instrumentation, Zhejiang Key Laboratory of Optoelectronic Information Technology, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
  • 3Squareroot8 Technologies Pte Ltd, Singapore
  • 4Centre for Quantum Technologies, National University of Singapore, Singapore
  • 5Global Technology Applied Research, JPMorganChase, New York, New York 10017, USA
  • 6IonQ, College Park, Maryland 20740, USA
  • 7IonQ Italia, Rome, RM, Italy

  • *Contact author: zhanggong@zju.edu.cn
  • †Contact author: charles.lim@nus.edu.sg
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PRX Quantum 7, 020353 – Published 5 June, 2026

DOI: https://doi.org/10.1103/h7kt-m5fc

Abstract

The power of quantum random number generation is more than just the ability to create truly random numbers—it can also enable self-testing, which allows the user to verify the implementation integrity of critical quantum components with minimal assumptions. In this work, we develop and implement a self-testing quantum random number generator (QRNG) chipset capable of generating 15.33 Mbits of certifiable randomness in each run, producing an expansion rate of 5.11×10−4 at a repetition rate of 10 MHz, with quantum side information considered for a high level of security. The chip design is based on a highly loss-and-noise-tolerant measurement-device-independent protocol, where random coherent states encoded using quadrature phase shift keying are used to self-test the integrated homodyne detectors—well-known to be challenging to characterize in practice. Importantly, this proposal opens up the possibility of implementing miniaturized self-testing QRNG devices at production scale using standard silicon photonics foundry platforms.

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Physics Subject Headings (PhySH)

Popular Summary

Random numbers are essential for secure communication, from online banking to data encryption. However, conventional random number generators either rely on algorithms, which are not truly random, or physical processes that can be silently manipulated by an attacker. This work introduces a silicon photonic chip that generates random numbers whose security can be verified in real time, without needing to fully trust the chip’s internal components. The chip uses the inherent unpredictability of quantum light and a self-testing procedure that continuously checks its own behavior. If the chip operates as expected, the output numbers are certified random; if any component degrades or is tampered with, the chip simply aborts the process. The result is a miniaturized, room temperature device that can be mass produced using standard silicon photonics foundries. In the future, such chips could be integrated into everyday electronics, bringing provably secure randomness to a wide range of applications.

Article Text

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PRX Quantum 7, 020353– Published 5 June, 2026
  • Received 14 September 2025
  • Revised 28 March 2026
  • Accepted 21 April 2026
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