Researchers from Boston University, the University of California, Berkeley, and Northwestern University have developed an integrated system that integrates electronic, photonic and quantum components on a single semiconductor chip, a first in the field of quantum technology, according to a new study published in Nature Electronics. The team's research proposes a way to mass-produce "quantum light factories" using semiconductor manufacturing processes commonly used in traditional electronic devices.
The new chip uses a standard 45nm semiconductor process to integrate a quantum light source and electronic controller. This approach paves the way for scaling quantum systems in areas of computing, communications, and sensing that have traditionally relied on hand-fabricated devices confined to laboratory settings.
“Quantum computing, communications and sensing are still decades away from concept to reality,” said Miloš Popović, associate professor of electrical and computer engineering at Boston University and senior author of the study. "This is a small step on that path, but an important one because it shows we can build repeatable, controllable quantum systems in commercial semiconductor foundries."
The chip at the heart of the research acts as a series of quantum light sources, known as microring resonators. Each device is less than a millimeter in diameter and can produce pairs of closely correlated photons, a key resource for quantum operations.
The packaged circuit board containing the chip was placed under a microscope at the detection station during the experiment.
Microring resonators operate by synchronizing with incident laser light, but their performance is highly sensitive to even slight temperature fluctuations or manufacturing changes—factors that can easily disrupt the delicate quantum processes they support.
To address these challenges, researchers developed an integrated control system capable of stabilizing microring resonators in real time. The chip contains 12 resonators that can operate in parallel, each of which is monitored by a built-in photodiode and tracks alignment with the laser. On-chip heaters and logic circuitry automatically adjust the resonator when temperature changes or other disturbances affect its performance.
“What excites me most is that we embed control directly on the chip to stabilize the quantum process in real time,” said Anirudh Ramesh, a doctoral student at Northwestern who led the quantum measurements. "This is a critical step toward scalable quantum systems."
This focus on stability is critical to ensuring each light source operates reliably under varying conditions. Imbert Wang, a doctoral student in photonic device design at Boston University, emphasized the technical complexity.
"In contrast to our previous work, a key challenge was to push photonics designs to meet the demanding requirements of quantum optics while staying within the tight limitations of commercial CMOS platforms. This enables electronics and quantum optics to be co-designed as a unified system."
Left, center, right: graduate student authors Imbert Wang, Daniel Kramnik and Josep Fargas, second left and second from right: Professor Milos Popovic and Professor Prem Kumar, senior authors of the study.
With tight feedback control of each light source, the chip maintains consistent performance even with temperature fluctuations or small manufacturing differences. The entire device is fabricated using commercial complementary metal oxide semiconductor processes and developed in collaboration with industry partners such as GlobalFoundries and Silicon Valley startup Ayar Labs.
The project required deep interdisciplinary collaboration. "The interdisciplinary collaboration required for this work is exactly what is needed to move quantum systems from the laboratory to a scalable platform," said Prem Kumar, a professor at Northwestern University and a pioneer in quantum optics. "We wouldn't be able to do this without the collaborative efforts of the fields of electronics, photonics and quantum measurement."