Physicists at MIT and Harvard University have made a groundbreaking discovery in understanding the superconductivity of ‘magic-angle’ graphene, a material with immense potential for future quantum computing devices.
Superconducting materials have long fascinated scientists due to their ability to conduct electricity with zero resistance. A key aspect of this phenomenon is the ease with which electron pairs, or ‘Cooper pairs‘ , can flow through these materials. Physicists at MIT and Harvard University have made a significant breakthrough in understanding the superconductivity of ‘magic-angle‘ graphene by directly measuring its superfluid stiffness.
Graphene is a two-dimensional material composed of carbon atoms arranged in a hexagonal lattice.
It was first isolated in 2004 by Andre Geim and Konstantin Novoselov, who were awarded the Nobel Prize in Physics for their discovery.
Graphene exhibits exceptional electrical conductivity, mechanical strength, and thermal properties.
Its unique structure allows it to be used in various applications, including electronics, energy storage, and composites.
Researchers are exploring its potential in fields such as medicine, water purification, and aerospace.
Superfluid stiffness refers to the ease with which a current of ‘electron pairs’ can flow through a material. This property is crucial for understanding the mechanism of superconductivity in magic-angle graphene, a material that has shown great promise for future quantum computing devices. To measure superfluid stiffness, the researchers developed a new experimental method that can be used to study other two-dimensional superconducting materials.
The challenge in measuring superfluid stiffness in atomically thin materials like magic-angle graphene lies in attaching these delicate materials to the surface of a microwave resonator without causing significant loss or degradation of the signal. The researchers overcame this hurdle by using techniques developed by ‘Will Oliver’s group’ at MIT, which involve precisely connecting extremely delicate two-dimensional materials.
The measurements revealed that magic-angle graphene‘s superconductivity is primarily governed by quantum geometry, which refers to the conceptual ‘shape‘ of quantum states that can exist in a given material. The researchers found that the superfluid stiffness was much larger than what conventional theories of superconductivity would have predicted, with a temperature dependence consistent with what the theory of quantum geometry predicts.
Quantum geometry is a theoretical framework that combines quantum mechanics and general relativity.
It describes the geometry of spacetime at the smallest scales, where classical notions of space and time break down.
This field of study aims to merge the principles of quantum physics with Einstein's theory of gravity.
Quantum geometry is still an emerging area of research, but it has potential applications in fields such as cosmology, particle physics, and condensed matter physics.
This research represents a significant step forward in understanding the superconductivity of magic-angle graphene and has implications for the development of future quantum computing devices. The findings also highlight the importance of quantum geometry in governing superfluid stiffness, which could lead to new insights into the behavior of other two-dimensional superconducting materials.
The discovery of magic-angle graphene‘s remarkable properties has sparked a wave of research and excitement among scientists. As this field continues to advance rapidly, we can look forward to unlocking the secrets of superconductivity and integrating this remarkable property into our daily lives.
