Quantum electronics will use graphene

"At the time, physicists were just starting to talk about the potential of quantum technologies and quantum computers," 36-year-old Mickael Perrin recalled of his career beginnings 12 years ago. "Today there are dozens of start-ups in this area, and governments and companies are investing billions in developing the technology further. We are now seeing the first applications in computer science, cryptography, communications and sensors."

Perrin's research has married thermodynamics and quantum mechanics in a new field of electricity production – with almost zero energy loss – using quantum effects.

While heading a research group at Swiss Federal Laboratories for Materials Science and Technology, better known as Empa, as well as being an assistant professor of quantum electronics at ETH Zurich, the quantum physicist has been honored with two awards over the past year – the highly sought-after ERC Starting Grant and an Eccellenza Professorial Fellowship of the Swiss National Science Foundation.

"It was mainly curiosity that pushed me in the direction of physics. I wanted to gain a better understanding of how the world around us works, and physics offers excellent for doing just that," he said.

Perrin was more interested in concrete applications than theory and became fascinated with engineering tiny devices at the micro- and nanoscale levels, recognizing the possibilities of molecular electronics.

Working in a nano-lab cleanroom while studying for his doctorate provided the technological infrastructure to build machines a few nanometers in size – over 300 times smaller than can be seen by the human eye, with an eyelash averaging 80,000 to 100,000 nanometers wide.

Graphene nanoribbons

Circuits can be given different characteristics depending on the materials used, becoming diodes, sensors, or transistors.

Between Empa, ETH Zurich and the IBM Research Center in Rüschlikon, Switzerland, Perrin has everything needed to produce and test nanostructures.

"Switzerland was a good choice for me for several reasons," he says. "The research infrastructure is unparalleled."

Graphene nanoribbons, which are manufactured at only one carbon atom thick and at various widths, offer unique properties that can be utilized across a wide spectrum of quantum technologies.

In 2018, quantum effects were proved to efficiently convert thermal energy into electricity, but only at very low temperatures – close to absolute zero.

Perrin's group at Empa circumvented this problem by using graphene nanoribbons, whose properties are much less impacted by temperature, demonstrating that the quantum effects of graphene are largely preserved even at 250 Kelvin (about minus 10 F or minus 23 C). Ideally, these structures will one day perform at room temperatures.

Challenges to come

Before we see nanotechnology powering smartphones, nanoscale power plants still have some hurdles – an estimated 15 years of continuing research, according to Perrin. The young physicist, however, is making headway. Working with colleagues from China, the United Kingdom, and Switzerland, Perrin recently demonstrated that carbon nanotubes just one nanometer in diameter can be integrated as electrodes.

"As a general rule, the smaller the structure you want to build, the bigger and more expensive the machine you will need to do so," explained Perrin. "Nanofabrication and experimental physics require a lot of creativity and patience, because something nearly always goes wrong. Yet, it's the strange and unexpected results that often turn out to be the most exciting."

Specialized equipment and components are required to test each built system. Lithography machines are used to pattern complex mini-circuits on microchips. Clean rooms and full-body suits are necessary to keep dust particles from contaminating the tiny structures.

"My aim is to work out the fundamental basis for applying this technology," said Perrin. "Only then will we be able to gauge its potential for practical uses."

The success of this meticulous work by the quantum physicist could result in a new generation of microelectronics with nanoscale power plants that transform waste heat into electricity.