Diamond's newfound defect may tame vibrations that hinder quantum light sources
Researchers in the Department of Electrical and Computer Engineering at the University of Illinois Urbana-Champaign have discovered a new type of quantum light emitter in diamonds that could help overcome a number of challenges facing quantum technologies.
The research was led by ECE graduate student Swetapadma Sahoo in Assistant Professor Simeon Bogdanov's research group, with contributions from undergraduate students Jaden Li and Darwon Kim. The Illinois team also collaborated with researchers from Oak Ridge National Laboratory, UCLA and international partners in France and Russia.
The findings, published in Nature Communications, introduce a newly identified diamond color center, named IL1 after the University of Illinois. The IL1 center emits exceptionally bright, narrowband quantum light consisting of single photons while remaining remarkably insensitive to the crystal vibrations typical in a diamond lattice.
Bogdanov said, "Diamond is not just a beautiful gemstone. It is an important technological material for electronics, optics, machining and medicine."
A defect that stays stable
The crystal structure of diamonds can host atom-scale defects known as color centers, which behave like artificial atoms capable of emitting individual particles of light. These color centers have long been viewed as promising components for quantum technologies, but their performance is often disrupted by tiny vibrations within the diamond crystal.
Those vibrations often distort or suppress the light emitted, requiring most existing quantum systems to operate at deeply cryogenic temperatures of a few degrees above absolute zero to suppress lattice vibrations.
The newly discovered IL1 center behaves differently.
Instead of coupling to many bulk crystal vibrations, the IL1 couples to a single, well-behaved local vibration. This specific vibration does not significantly spoil the emission but instead has the potential to be controlled and used as a novel quantum resource.
Imagine riding on a high-speed maglev train. Although the train travels at remarkable speeds through turbulent air and rough terrain, a glass of wine resting inside remains perfectly still. The Illinois researchers found that the IL1 center behaves similarly. While the surrounding diamond crystal vibrates, the color center remains remarkably isolated, producing bright quantum light with a well-defined frequency.
Higher-temperature quantum devices
This unique behavior could eliminate one of the major barriers to practical quantum devices. Color centers like the IL1 could operate at substantially higher temperatures, dramatically simplifying the hardware needed for future quantum communication systems, sensors and information technologies.
"Instead of fighting the vibrations within the material, we've discovered a system that interacts with a single, well-behaved vibration that we may eventually be able to control and use," Bogdanov said. "This gives us a completely new way of thinking about how color centers can be engineered."
For Bogdanov, publication in Nature Communications represents more than recognition of the team's work. The work also provides a foundation for future research. By revealing a previously unknown physical mechanism for controlling quantum behavior, the discovery could guide the design of improved quantum emitters in diamond and other materials while advancing practical applications in secure communications and nanoscale sensing.
"By showing that we can suppress phonon coupling, a longstanding obstacle in this field, we open the door to a new generation of candidates for quantum applications," Sahoo said. "The discovery of such novel quantum materials will be essential not only to understanding the physics at play, but ultimately to engineering these systems by design."
The next questions for IL1
"What excites us most is that this is just the beginning."
"This publication gives us momentum to pursue the next set of questions," Bogdanov said. "Can we control the spin and charge of the new IL1 center? Can we build a quantum memory using its unique vibrational properties? Can we engineer similar defects in other materials? We have a multi-year research program planned to explore these questions."
Publication details
Swetapadma Sahoo et al, Ultranarrow bright single-photon emitters in diamond with strong broadband phonon decoupling, Nature Communications (2026). DOI: 10.1038/s41467-026-74662-0
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Citation: Diamond's newfound defect may tame vibrations that hinder quantum light sources (2026, July 31) retrieved 31 July 2026 from https://phys.org/news/2026-07-diamond-newfound-defect-vibrations-hinder.html
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