Scientists at the Massachusetts Institute of Technology have ascertained that a particular arrangement of five layers of graphene results in a unique multiferroic state, characterized by non-traditional magnetism and a newly identified form of electronic behavior referred to as “ferro-valleytricity.” Such a discovery has the potential to significantly impact the future design of high-storage and energy-efficient data storage systems.
A recently unveiled electronic attribute within a five-layer structure of graphene could facilitate the enhancement of data density in magnetic memory technologies.
Graphite, the common material in pencil lead, reveals remarkable characteristics when reduced to atomic-thin layers. One of these monolayer structures is known as graphene, which is exceedingly fine—much finer than a strand of human hair. Examined microscopically, this material appears as a hexagonal lattice of carbon atoms, akin to chicken wire.
Although fragile in appearance, over time researchers have established that graphene possesses extraordinary strength. Moreover, when configured in specialized layer arrangements and twists, it exhibits unanticipated electronic properties.
Scientists at MIT have now identified an additional unusual characteristic in graphene. When organized into a stack of five layers in a rhombohedral formation, the material enters into an uncommon multiferroic phase, displaying both non-traditional magnetism and a new form of electronic behavior, which they have termed ferro-valleytricity.
This discovery has the capacity to aid engineers in creating highly efficient and high-capacity data storage solutions, applicable to both classical and quantum computing systems.
“Being a multiferroic material enables the possibility of storing twice the amount of data compared to standard devices, while also achieving energy and time efficiencies in writing to a magnetic hard drive,” notes Long Ju, assistant professor of physics at MIT and the leader of the research team.
The research findings will be detailed in an upcoming edition of the journal Nature, with contributions from Tonghang Han, Zhengguang Lu, Tianyi Han, and Liang Fu from MIT, alongside researchers from Harvard University and the National Institute for Materials Science in Japan.
Table of Contents
Understanding Multiferroic Characteristics
A material that exhibits coordinated behavior in its electrical, magnetic, or structural attributes is defined as ferroic. A conventional example is a magnet, wherein electrons align their spins in a unified direction without external magnetic influence. However, only a very limited number of materials have been identified to be multiferroic—exhibiting multiple forms of coordinated behavior. In such materials, not only does the magnetic orientation align in a certain direction, but the electric charge also shifts in an independent direction.
Multiferroic materials hold immense promise in electronics, particularly in the realm of hard drives. Existing magnetic hard drives utilize a significant amount of energy and operate at slow speeds when switching magnetic domains, read as 1 or 0 based on their orientation. If multiferroic materials were integrated into storage devices, switching could be achieved using a rapid, low-power electric field.
The research team conducted preliminary calculations and discovered that in a rhombohedral five-layer arrangement of graphene, electrons exhibit collective behavior. Subsequent laboratory experiments confirmed the emergence of two sets of coordinated ferroic behaviors, constituting a rare multiferroic state.
The researchers were able to control these multiferroic properties using an electric field, suggesting that the incorporation of such materials into memory chips could potentially double the data storage capacity compared to conventional multiferroics.
This work was partially supported by funding from the National Science Foundation and the Sloan Foundation.
Reference: “Orbital Multiferroicity in Pentalayer Rhombohedral Graphene,” 18 October 2023, Nature.
DOI: 10.1038/s41586-023-06572-w
Frequently Asked Questions (FAQs) about multiferroic graphene
What did MIT physicists discover about graphene?
MIT physicists discovered that when graphene is stacked in a specific five-layer pattern, it exhibits a unique “multiferroic” state. This state includes unconventional magnetism and a novel electronic behavior named “ferro-valleytricity.”
What potential applications does this discovery have?
This discovery could pave the way for the development of high-capacity, energy-efficient data storage devices for both classical and quantum computers.
What is ferro-valleytricity?
Ferro-valleytricity is a new type of electronic behavior identified in graphene when it is stacked in a five-layer pattern. In this state, electrons in the material coordinate and prefer to settle in one energy valley over another.
How is this graphene different from ordinary graphite?
Graphene is a single, atom-thin sheet of graphite. Unlike ordinary graphite, which is used in pencil leads, this five-layered arrangement of graphene demonstrates unique multiferroic properties.
How was this discovery made?
The research team carried out experiments at temperatures just above absolute zero to dampen other effects, such as thermal disorders. They then measured the electrons’ response to electric and magnetic fields and discovered two sets of coordinated ferroic behaviors in the five-layer graphene.
What are multiferroic materials?
Multiferroic materials are rare substances that exhibit coordinated behavior in multiple domains like electric, magnetic, or structural properties. They hold significant potential for electronics because they could increase speed and lower the energy cost of hard drives.
Who funded this research?
This research was funded, in part, by the National Science Foundation and the Sloan Foundation.
Where can I find the full report of this discovery?
The full report of this discovery can be found in a forthcoming paper in the journal Nature, under the title “Orbital Multiferroicity in Pentalayer Rhombohedral Graphene.” The DOI for the paper is 10.1038/s41586-023-06572-w.
More about multiferroic graphene
- MIT Physics Department
- Nature Journal
- National Science Foundation
- Sloan Foundation
- Graphene Research
- Quantum Computing
- Classical Computing
- Data Storage Solutions
- Multiferroic Materials
- DOI for the Nature paper
9 comments
i mean, i’ve heard graphene was a wonder material, but this is next level. kudos to the MIT team.
Multiferroic properties in graphene, huh? That can change the way we store data and even process transactions. Blockchain, meet graphene?
Wow, this is game changing stuff! Who would’ve thought pencil lead, broken down like that, could be so powerful? Multiferroic and all?
This could have huge implications for data storage. Energy efficient and high capacity? sounds like the future of tech to me.
dunno about the tech aspects but any discovery that can double data while reducing energy is a win in my book.
Energy efficiency is the keyword for me. If this tech makes it to mainstream, it’s not just a win for computing but for the environment too.
Not much into physics, but if this trickles down to consumer electronics, I’m all in. Faster hard drives here we come!
Stacked in five layers and you get unique properties? This could bring quantum computing to a whole new level.
So many breakthroughs in graphene research these days. It’s like every layer adds another layer of possibilities. Literally.