Di ZHU

He made significant contributions on two technological platforms,superconducting nanowire detectors and lithium niobate photonics, to promote the construction of scalable photonic quantum processors.

Quantum information processing, harnessing the laws of quantum physics, holds the potential to revolutionize our modern society by addressing complex problems in areas such as cybersecurity, logistics optimization, and drug discovery. Optical photons are natural carriers of quantum information and well-suited to implement quantum processors.

However, constructing a utility-scale quantum system to solve practical problems requires putting together thousands to millions of components. This would be almost impossible using traditional bulk optical devices.

Assistant Professor Di Zhu from the National University of Singapore has been devoted to developing scalable hardware for photonic quantum information processing. Focusing on integrated photonics, he developed a range of novel devices for on-chip single-photon generation, control, and detection.

By engineering superconducting nanowires into slow-wave transmission lines, Di and his colleagues developed a delay-line multiplexing architecture, allowing large detector arrays to be read out using just one pair of RF cables, substantially reducing the heat load to cryostats. By engineering the impedance of the nanowires, he developed the superconducting tapered nanowire detector (STaND), enabling photon-number resolution. These advancements significantly extended the functionality and performance of superconducting nanowire single-photon detectors (SNSPDs) and brought direct impact to a wide range of photonic quantum applications.

Utilizing the excellent electro-optic properties of thin-film lithium niobate (TFLN), he implemented a double-pass phase modulator to control the color and shape of single photons. On the same platform, he further developed a novel phase-matching scheme based on “layer poling” for entangled photon-pair generation.

Going forward, Di will continue to develop new devices for quantum applications. At the same time, he will work with photonics foundries to realize wafer-scale fabrication of quantum photonic integrated circuits and also explore new material systems.