Quantum light sources, often described as the building blocks of next-generation technologies like quantum computing and quantum communication, have long been a subject of intense research. However, despite their potential, these sources can be unpredictable, flickering and fading in a way that limits their practical use. But a groundbreaking study from the University of Oklahoma (OU) has uncovered a method to stabilize these light sources, specifically a type known as colloidal quantum dots (QDs). The research, published in Nature Communications, promises to unlock new possibilities for affordable and scalable quantum technologies, offering a path to stable quantum light sources that can be used in real-world applications.
What Are Quantum Dots?
At the heart of this discovery are quantum dots (QDs), a class of nanomaterials with remarkable optical properties. These tiny semiconductor particles are so small that, if scaled up to the size of a baseball, a single quantum dot would be as large as the moon. Despite their size, quantum dots exhibit quantum mechanical behaviors that make them perfect for applications in displays, biomedical engineering, solar cells, and, crucially, in quantum computing and communication.
Quantum dots are typically sensitive to their environment, particularly the defects on their surface, which can cause them to malfunction. In quantum technologies, photon emission plays a crucial role. Quantum computers, for example, rely on single-photon emitters to encode and transfer information. However, QDs have faced significant challenges in this regard due to their instability. The surface defects can cause flickering, also known as blinking, and darkening, which impedes their ability to emit photons continuously.
Stabilizing Quantum Dots: The Key Discovery
The research led by OU Assistant Professor Yitong Dong sought to address these issues by stabilizing the quantum dots to prevent them from flickering or fading. Dong and his team discovered that by adding a crystallized molecular layer to the surface of perovskite-based quantum dots, they could neutralize the surface defects and stabilize the surface lattices. This coating not only protected the quantum dots but also enhanced their photon emission, enabling them to shine continuously without degradation.
“In quantum computing, you must be able to control how many photons are emitted at any given time,” Dong explained. “QDs are notoriously unstable, so we worked to create a crystal covering that could stabilize their quantum emissions. This material is ideal because it is inexpensive to use and scale and is efficient at room temperature.”
By stabilizing the QDs, Dong’s team managed to prevent their usual decay and blinking behavior. They were able to extend the continuous photon emission of these quantum dots to more than 12 hours—a remarkable improvement from the typical 10-20 minutes of stable use before QDs usually fail.
A Breakthrough for Practical Applications
Historically, quantum dots have been limited by two major challenges: their surface defects and the need for extremely low temperatures to operate. The first issue arises from the fact that quantum dots are so small that even a minor imperfection on their surface can disrupt their ability to function properly. These defects have been the main reason why quantum dots often fail after a very short period of use. The second issue is that single-photon emitters—devices that emit only one photon at a time, which is essential for many quantum applications—have required cryogenic temperatures for reliable operation. These temperatures, often achieved with liquid helium at -452°F (-269°C), are costly to maintain and impractical for most real-world applications.
Dong’s team overcame both of these hurdles with their innovative approach. By stabilizing the quantum dots with a crystalized molecular layer, they achieved nearly 100% efficiency at room temperature, which is a monumental breakthrough. This efficiency is achieved without the need for expensive cooling systems, making perovskite quantum dots a viable option for practical use in quantum computing and quantum communication.
The Significance of Perovskite Quantum Dots
The use of perovskite quantum dots represents a paradigm shift in the materials used for quantum technologies. Perovskites are a class of materials that have gained significant attention in recent years due to their optical and electronic properties, which make them ideal for use in various photonics applications. Perovskite quantum dots are particularly advantageous because they can be synthesized inexpensively and can operate at ambient temperatures. This is in stark contrast to traditional quantum emitters, which often require complex and expensive cooling systems to function.
As Dong noted, “Although there has been real interest in the exotic optical properties of this material, the sophistication needed to fabricate a single photon emitter was cost-prohibitive. But since perovskite QDs can be used at normal temperatures and synthesized for very little cost, we believe they could become the photonic chip light source for future quantum computing and quantum communication devices.”
This cost-effectiveness, coupled with the ability to operate at room temperature, opens up new possibilities for scaling quantum technologies. The potential applications for stable, room-temperature quantum light sources are vast, ranging from secure communications to quantum information processing and imaging. These developments could lead to more affordable, widespread adoption of quantum technologies in the coming years.
Implications for Future Quantum Research
Dong’s research is not just a breakthrough in the practical use of quantum dots; it also has significant implications for the fundamental physics of quantum materials. The stabilization technique developed by his team using organic and inorganic molecular crystals could serve as a platform for the development of new quantum emitters with enhanced properties. According to Dong, these findings could pave the way for future research into other quantum materials and optical properties that could further advance the field of quantum technology.
“In my opinion, our research has profound implications for the quantum field,” Dong said. “We’ve found a way to stabilize these quantum dots using organic and inorganic molecular crystals, opening the door for others to explore the fundamental optical properties and fundamental physics of these materials. It’s really exciting.”
The breakthrough in stabilizing quantum dots with perovskite crystals not only accelerates the development of quantum computing but also contributes to a deeper understanding of quantum materials. As researchers continue to explore new ways to manipulate these materials, it is likely that even more advancements will come, leading to the creation of quantum technologies that are more affordable, scalable, and efficient than ever before.
Conclusion
The recent research from the University of Oklahoma represents a game-changing advancement in the development of quantum light sources. By stabilizing colloidal quantum dots with a crystalized molecular layer, researchers have solved some of the most persistent challenges in quantum technologies, including surface defects, photon decay, and the need for extreme cooling temperatures. The discovery of room-temperature, stable quantum dots opens up new possibilities for practical applications in quantum computing, communication, and beyond.
As we look ahead, the use of perovskite quantum dots could pave the way for the development of affordable, scalable, and high-efficiency quantum technologies that are accessible to a broader range of industries and applications. With this breakthrough, the future of quantum computing and communication seems much brighter, ushering in a new era of quantum innovation.
Reference: Mi, C. et al. Towards non-blinking and photostable perovskite quantum dots, Nature Communications (2025). DOI: 10.1038/s41467-027-55619-7, www.nature.com/articles/s41467-024-55619-7