A team of physicists at MIT has made a groundbreaking discovery that challenges long-held assumptions about superconductors: a new type of superconductor with magnetic properties, dubbed chiral superconductivity, has been found in ordinary graphite.
A team of physicists at the Massachusetts Institute of Technology (MIT) has made a groundbreaking discovery that challenges long-held assumptions about superconductors. In a paper published in Nature, the researchers have found a new type of superconductor that is also magnetically ordered.
Established in 1861, MIT is one of the world's premier research universities.
Located in Cambridge, Massachusetts, it is known for its programs in science, technology, engineering, and mathematics (STEM).
With a strong focus on innovation and entrepreneurship, MIT has produced many successful startups and companies.
The university has a long history of academic excellence, with 98 Nobel laureates among its faculty and alumni.
What is Chiral Superconductivity?
Chiral superconductivity refers to the phenomenon where a material exhibits both zero electrical resistance and intrinsic magnetic properties. This is unusual because most superconductors do not exhibit magnetism, and vice versa. The MIT team has observed this behavior in ordinary graphite, which is made up of many layers of graphene – atomically thin, lattice-like sheets of carbon atoms.
Chiral superconductivity is a phenomenon where a material's Cooper pairs exhibit chirality, meaning they have a specific handedness or spin orientation.
This leads to unique properties such as zero-energy states and edge currents.
Chiral superconductors are typically found in materials with strong spin-orbit coupling, like certain heavy fermion compounds.
Research on chiral superconductivity has implications for topological quantum computing and the study of exotic matter.
The Discovery
To make the discovery, the researchers isolated microscopic flakes of rhombohedral graphene from graphite and subjected them to a series of electrical tests. They found that when cooled to 300 millikelvins (about -273 degrees Celsius), the material turned into a superconductor. The team also observed that when they swept an external magnetic field up and down, the flakes could be switched between two different superconducting states, just like a magnet.
Theoretical Explanation
According to the researchers, the unique configuration of rhombohedral graphene is key to this phenomenon. When cooled to ultracold temperatures, thermal fluctuations are minimized, allowing electrons flowing through the material to slow down and sense each other. This leads to quantum interactions that can cause electrons to pair up and superconduct.
Implications
The discovery of chiral superconductivity has significant implications for our understanding of materials science and physics. The researchers suspect that this phenomenon may be related to a new type of topological superconductor, which could enable robust quantum computation.
A topological superconductor is a type of material that exhibits both zero electrical resistance and topological properties.
This phenomenon occurs when the material's electronic structure is protected by symmetry, allowing it to maintain its unique properties even in the presence of defects or impurities.
Topological superconductors are of great interest for their potential applications in quantum computing and other emerging technologies.
A New Era in Superconductivity Research
The MIT team’s discovery is an exciting development in the field of superconductivity research. As one researcher noted, ‘Everything we’ve discovered in this material has been completely out of the blue.‘ The team’s findings have the potential to revolutionize our understanding of materials and could lead to breakthroughs in fields such as energy storage and quantum computing.
Experimental Methods
The researchers used a range of experimental methods to study the properties of rhombohedral graphene. These included electrical testing, magnetic field sweeps, and theoretical modeling. The team also collaborated with researchers from Florida State University, the University of Basel in Switzerland, and the National Institute for Materials Science in Japan.
Future Directions
The discovery of chiral superconductivity opens up new avenues for research in materials science and physics. Future studies will aim to understand the underlying mechanisms that drive this phenomenon and explore its potential applications. As one researcher noted, ‘It is truly remarkable that such an exotic chiral superconductor emerges from such simple ingredients.‘
