Unlock the secrets of ultrathin materials with a groundbreaking discovery in magnetism, revealing new possibilities for quantum materials research.
Unlocking the Secrets of Ultrathin Materials: Physicists Discover Unexpected Magnetism
A team of researchers at MIT has made a groundbreaking discovery in the field of ultrathin materials, revealing unexpected magnetism in an atomically thin material. This finding introduces a new platform for studying quantum materials and opens up exciting possibilities for further research.
The Power of Twistronics
Ultrathin materials have been a subject of intense interest since the discovery of graphene 20 years ago. By stacking individual sheets of these 2D materials and twisting them at slight angles, researchers have created new properties such as superconductivity and magnetism. This field of research is known as twistronics, pioneered by Pablo Jarillo-Herrero, the Cecil and Ida Green Professor of Physics at MIT.
A Helical Structure with Unusual Properties
The researchers worked with three layers of graphene, each twisted on top of the next at the same angle, creating a helical structure similar to the DNA helix or a hand of three cards fanned apart. This unique arrangement results in a moiré lattice pattern that affects the behavior of electrons.
A Major Surprise: Orbital Magnetism
The team expected to observe signatures of the moiré hierarchy but were surprised when they applied and varied a magnetic field. The system responded with an experimental signature for magnetism, which arises from the motion of electrons. This orbital magnetism persisted even at extremely low temperatures, -263 degrees Celsius.
Unlocking the Mystery
The researchers were puzzled by this unexpected finding, as the new material should have lacked the specific symmetry required for orbital magnetism to occur. However, further investigation revealed that the atoms in the system underwent a subtle orchestrated movement called lattice relaxation, breaking the symmetry locally on the moiré length scale.
A New Platform for Quantum Materials Research
This discovery opens up new possibilities for studying quantum materials and understanding how electrons behave in complex systems. The researchers’ findings demonstrate that the moiré hierarchy can support interesting phenomena at different length scales, providing a rich platform for further exploration.
Supporting Organizations
The work was supported by various organizations, including the Army Research Office, the National Science Foundation, the Gordon and Betty Moore Foundation, and the Ross M. Brown Family Foundation.
This groundbreaking research has significant implications for our understanding of quantum materials and the behavior of electrons in complex systems. As researchers continue to explore this new platform, we can expect exciting breakthroughs in the field of ultrathin materials.
