August 15, 2024

Driving smaller, faster and greener technology with quantum materials

By Hannah Ashton

Photos by Karl Maasdam

𝕏

Physicist Ethan Minot and graduate student Brett Clark operate a machine to dry-transfer van der Waals materials. This process enables the precise peeling and stacking of single atomic layers, allowing researchers to create ultrathin, layered materials for advanced scientific exploration.

How often do you stop throughout your day to consider the miniaturized technology that powers your cell phone — a device many of us can’t live without?

As the components continue to shrink and become more powerful, the industry is keenly interested in identifying the next breakthrough material to revolutionize the field.

Physicist Ethan Minot and his lab are focused on exploring potential applications for a new category of materials that defy classical physics — quantum materials. Quantum materials offer endless possibilities including making technology smaller, more energy efficient and even faster. His lab not only uncovers new applications for these materials but also connects students with industry leaders, cementing career pathways with Oregon technology sector leaders like Intel.

“Working with the electronic and optical properties of new materials, to me it feels like a great endless process of finding new things out,” Minot said. “That’s why it’s so fun to stay in the field.”

A man points to a piece of technology in a lab while a group of male students observe.

Members of the Minot lab gather around the light source of the spectrally resolved photocurrent microscope, a tool used to measure a device's response to various wavelengths of light.

Thinner than a human hair

The Minot lab specializes in numerous nanoscale systems such as carbon nanotubes, graphene and two-dimensional semiconductors, the last of which resulted in an international collaboration with scientists in Finland.

“There are many quantum materials in our toolkit to play with, and our lab has pushed the envelope in carbon nanotubes, making devices where the nanotubes are longer, cleaner and with more information about their atomic structure,” Minot said.

Carbon nanotubes, nanoscale hollow tubes composed of carbon atoms, are more than 50,000 times thinner than a human hair. They have applications in automotive parts, electrical circuitry, supercapacitors, transistors, fuel cells, batteries and more.

Graphene, another promising tiny material, is made of a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice.

Although the size is beneficial for keeping devices small, it makes both materials tricky to work with. The Minot Lab has worked to overcome this hurdle by using microscopy and lithography techniques to both see and interact with microscopic materials.

Another option for keeping technology small is layering ultra-thin materials on top of each other.

“In biblical times, we wrote by chipping into a stone block and you’d have to carry around a very heavy tablet,” Minot said. “Finally, we invented paper and now a book can have a thousand pages and we can carry it around easily.”

Currently, technology using silicon, one of the most widely used materials in the electronic industry, works similarly to a stone tablet. Circuits are engraved on the top surface, but the third dimension is not used.

By moving towards thin, stackable materials, researchers could add more “pages,” allowing devices to do more while also maintaining a small size.

“I think it’ll take a lot of effort for the industry to figure out how to make these books with so many pages, but it gives hope and promise to the whole field,” Minot said.

Minot’s work with two-dimensional semiconductors resulted in an international study published in Science in 2022. He collaborated with Aalto University in Finland to develop a powerful, ultra-tiny spectrometer that fits on a microchip and is operated using artificial intelligence. Spectrometers measure and analyze the properties of light, helping to identify the composition and characteristics of substances. Contributing to a field known as optical spectrometry, this device could improve everything from smartphone cameras to environmental monitoring.

The research involved two-dimensional semiconductors, a relatively new class of super thin materials that can control the flow of electricity, allowing them to serve as the foundation for many electronics.

Traditional spectrometers rely on bulky components, while the one Minot helped with could fit on the end of a human hair. The finished product doesn't require assembling separate optical and mechanical components or array designs to disperse and filter light. It can also achieve a high resolution compared to old methods and in a much smaller package. The device is 100% electrically controllable regarding the colors of light it absorbs, making it easily scalable and applicable to numerous fields.

A man in a blue shirt with black gloves points at a machine while two male students observe.

Physicist Ethan Minot shows undergraduate students Ethan Hogan (left) and Miller Nelson (right) how to operate an electron beam evaporator. This machine evaporates metal onto samples, a crucial step in creating metal contacts for devices in the lab.

Launching careers with industry access and practical experience

There are tremendous advantages to researching new materials at Oregon State, including collaboration and industry pathways. The College of Science works closely with the College of Engineering and shares the facilities needed to build tiny devices. Minot, who works in a clean room on the Corvallis campus, looks forward to the anticipated Collaborative Innovation Complex clean room that will offer more space to study sensitive materials.

“The ecosystem in Oregon is a great place for doing this research as well,” he said. “The proximity to Intel has been both a great career pathway for my students and also donations of equipment and talking to industry professionals about where they see their technology going and what applications they’re looking for.”

Many graduate students have landed positions at Intel in Hillsboro, Oregon. Others have joined startups focusing on technologies like biotechnology or remote sensing, and some have continued working in research.

“I think in my lab you get exposed to, ‘What is it like to work in a clean room? What are some of the standard industry methods for checking if a transistor is working? What’s it like dealing with companies when you have to order things?’ These are skills that someone in the industry would want you to be able to do, but you are not going to learn them by taking a class,” Minot said.

"Students need to find out if they thrive in a laboratory environment."

Undergraduates also have the opportunity to leave their mark. One such student entered the lab as a first-year transfer student. He had completed a few physics classes but was more interested in how the instrumentation works and how things were automated for efficiency.

“He came in with a lot of enthusiasm and was able to learn just as fast as the graduate students about the hands-on aspects of doing experimental physics,” Minot said.

Students need foundational textbook knowledge, but they also need hands-on experience, something the College of Science prioritizes. There is no class that will make you instantly ready to join a lab, Minot said. As long as students are enthusiastic and come in with a drive to learn, he is happy to teach the other skills.

“Students need to find out if they thrive in a laboratory environment. The only way to find out if you should be a researcher is to try it,” he said. “‘Do you get joy from tackling problems that seem insolvable, and can you engage with the process and be patient?’”

Six men pose for a group picture in a laboratory.

The Minot Lab poses for a group picture. The lab includes both undegraduate and graduate students.

Shaping the future of technology

Thanks to pioneering research like that done by Minot and his lab, the future of technologies holds exciting possibilities. Imagine cell phones in the future with lower energy consumption, faster processing speeds and even sleeker designs. Minot’s work pushes the boundaries of what’s technically feasible while preparing the next generation of researchers. Next time you use a computer or cell phone, take a minute to appreciate the cutting-edge science driving these tools and the people behind them.