Tangible progress towards graphene-based electronics

Dec. 22 () –

scientists from Georgia Institute of Technology have developed a new nanoelectronic platform that replaces silicon with graphene, a single sheet of carbon atoms.

technology is compatible with conventional microelectronics manufacturinga necessity for any viable alternative to silicon, according to Walter de Heer, professor at the Faculty of Physics and lead author of the research.

A pressing search in the field of nanoelectronics is for a material that can replace silicon.. Graphene has shown promise for decades. But its potential has faltered along the way, due to detrimental processing methods and the lack of a new electronic paradigm to embrace it. With silicon nearing the limits of its capacity to accommodate faster computing, the next great nanoelectronics platform is needed more now than ever.

In the course of his investigation, published in Nature Communications, the Georgia Tech team may have discovered a new quasiparticle as well. Its discovery could lead to the manufacture of smaller, faster, more efficient and more sustainable computer chips, and has potential implications for high-performance and quantum computing.

“The power of graphene lies in its two-dimensional planar structure, held together by the strongest known chemical bonds,” de Heer explains. it’s a statement. “It was clear from the beginning that graphene can be miniaturized much more than silicon: it makes it possible to create much smaller devices that run faster and produce much less heat. This means that, in principle, You can pack more devices into a single graphene chip than you can with silicon.”

In 2001, de Heer proposed an alternative form of electronics based on epitaxial graphene, or epigraphene: a layer of graphene that formed spontaneously on silicon carbide crystal, a semiconductor used in high-power electronics. The researchers then discovered that electrical current flows without resistance along the edges of epigraphene and that graphene devices can be interconnected without metallic wires. This combination enables a form of electronics that relies on the unique properties of graphene’s electrons, similar to light.

To create the new nanoelectronic platform, the researchers created a modified form of epigraphene on a silicon carbide crystal substrate. In collaboration with researchers at the International Center for Nanoparticles and Nanosystems at Tianjin University, China, they produced unique silicon carbide chips from electronic-grade silicon carbide crystals. The graphene was grown in de Heer’s lab at Georgia Tech using proprietary ovens.

The researchers used electron beam lithography, a common method in microelectronics, to carve the graphene nanostructures and weld their edges to silicon carbide chips. This process stabilizes and mechanically seals the edges of the graphene, which would otherwise react with oxygen and other gases that could interfere with the movement of charges along the edge.

Finally, to measure the electronic properties of their graphene platform, the team used a cryogenic apparatus that allows recording its properties from near zero to room temperature.

The electrical charges that the team observed at the edges of the graphene were similar to photons in an optical fiber that can travel great distances without scattering. They found that the charges traveled tens of thousands of nanometers along the edge before dispersing. Graphene electrons from earlier technologies could only travel about 10 nanometers before colliding with tiny imperfections and scattering in different directions.

“The special thing about edge electric charges is that they stay on the edge and keep moving forward at the same speed, even if the edges are not perfectly straight”, explains Claire Berger, Professor of Physics at Georgia Tech and Director of Research at the National Center for Scientific Research in Grenoble, France.

In metals, electrical currents are carried by negatively charged electrons. But contrary to what the researchers expected, their measurements indicated that the edge currents were not carried by electrons or holes (a term for positive quasiparticles indicating the absence of an electron). Rather, the currents were carried by a highly unusual quasiparticle that has no charge and no energy and yet moves without resistance. The components of the hybrid quasiparticle were observed to travel on opposite sides of the graphene edges, despite being a single object.

These unique properties indicate that the quasiparticle it could be one that physicists have been waiting decades to exploit: the elusive Majorana fermionpredicted by the Italian theoretical physicist Ettore Majorana in 1937.

“Developing electronics using this new quasiparticle in seamlessly interconnected graphene networks would be a game changer,” says de Heer.

According to de Heer, it will likely be five to ten years before we have the first graphene-based electronics. But thanks to the team’s new epitaxial graphene platform, the technology is closer than ever to crowning graphene the successor to silicon.