Mazumder Turns Gold (Nanoclusters) To Tech Innovations

Carnegie Mellon University chemistry Ph.D. student Abhrojyoti Mazumder struck gold with nanocluster research. Made in a lab, these materials could help make quantum computers and communication networks faster and more powerful — advances with far-reaching implications for national security, economic competitiveness and scientific leadership.

Progress in computing and communications depends on materials that can transmit light with greater precision and stability. Mazumder’s research into gold nanoclusters could make it easier and more reliable to send light signals through fiber-optic networks already in use.

“We hope in the future, they can be integrated into photonic chips engineered to operate at telecommunication wavelengths, enabling seamless interaction with the spectral bands used in fiber-optic telecom systems,” said Mazumder.

Unlike other nanoscale materials such as quantum dots or carbon nanotubes, gold nanoclusters can be produced with remarkable uniformity and tunable optical properties, traits that make them ideal for precision quantum and photonic applications.

Building blocks for quantum and photonic technologies
Gold nanoclusters are a relatively new class of materials that can only be synthesized in a lab. They’re designed at the atomic scale — ranging from 24 atoms to 96 atoms long, which is 1 to 3 nanometers — and are in specialized geometric patterns. Typically, they have similar properties to other nanoparticles, which can be used as semiconductors. Unlike other nanoparticles, gold nanoclusters generally have no defects, and they are uniform in size, properties and chemical composition, making them more predictable and less prone to error. Chemists believe they have unusual properties.

Mazumder worked with Linda Peteanu and Rongchao Jin, professors of chemistry, to analyze gold nanoclusters through optical imaging techniques to see how they can potentially be used. Their findings point to applications that align with U.S. priorities in secure communications and quantum information science. Because gold nanoclusters don’t have defects, they could make it easier to build quantum and photonic chips at larger scales, with fewer errors and lower energy use.

Traditional telecommunications operate on certain wavelengths on the electromagnetic spectrum. In experimental conditions, Mazumder found that when gold nanoclusters emitted electromagnetic waves in the same area of the spectrum, they could lead to faster and more efficient communication.

Quantum computers use quantum bits, known as qubits, to encode information similar to traditional bits used in computers. While traditional bits encode 0 or 1 and work on one task at a time, qubits can encode 0 and 1 at the same time, which allows multiple scenarios to run simultaneously.

Laying the groundwork for quantum innovation
To create quantum computers, scientists need stable single-photon emitters, which allow particles of light to be used as qubits. Mazumder found that certain gold nanoclusters can efficiently produce stable single photons.

“They can generate single photons efficiently with a very high purity,” Mazumder said. “It has immense potential to work as an ideal single photon emitter in the future.” - Peteanu said that Mazumder’s work has potential for more applications.

“Though the path between a material showing promising properties and a working device of any kind is generally arduous, the experiments Abhro is performing will teach us a lot about the basic mechanism of light emission in these clusters and will therefore support the development of more mature applications, including as fluorescent labels for bioimaging,” Peteanu said.

Recognizing the strategic potential of his work, Mazumder earned the McWilliams Fellowship, a competitive honor supporting graduate researchers whose work advances leading-edge science in selected fields such as nanotechnology.

“Abhro is not only highly productive but also exceptional at initiating new projects and in aggressively pursuing professional opportunities such as funding to attend conferences,” Peteanu said. “He is outstanding at managing collaborations across groups and departments. I attribute our ability to obtain interesting results in an area that is very new to us to Abhro’s independence and can-do attitude.”

Mazumder said he looks forward to using the fellowship to dive further into his research.

“I’m grateful for the fellowship and for the support from Professor Peteanu and Professor Jin,” Mazumder said. “I’m really excited to further investigate these nanoclusters and explore their potential practical applications in next-generation quantum technologies.”