Rhombohedral Graphene: The New Frontier in Superconductivity

Scientists have made a big discovery in the world of materials science. They found something special in a type of graphene called rhombohedral graphene. This isn't your ordinary graphene. It's made up of four or five layers stacked in a specific way. What makes it special? It shows signs of something called chiral superconductivity. This is a rare and unusual state of superconductivity. Chiral superconductors are unique. They break something called time-reversal symmetry. This means if you reverse time, the system behaves differently. It's like watching a movie backward, and it doesn't make sense. These superconductors also have something called Cooper pairs at non-zero angular momentum. This is a fancy way of saying the electrons pair up in a unusual way. Why is this important? These states could host something called Majorana fermions. These are special particles that could be used in topological physics research. They could also be key to fault-tolerant quantum computing. This is a big deal because it could lead to more stable and powerful computers. For a long time, scientists have been looking for signs of chiral superconductivity. They've studied many different materials, but it's been hard to find. Until now. In this new study, researchers found robust superconductivity in rhombohedral graphene. They saw two superconducting states. These states had a critical temperature of up to 300 millikelvin. This is incredibly cold, but it's a significant finding. The researchers also found something interesting about the magnetic properties. In the superconducting state, the resistance showed magnetic hysteresis. This means the resistance changed in a specific way when a magnetic field was applied and then removed. This is different from other superconductors. The superconducting states were also robust against in-plane magnetic fields. This means they could withstand a magnetic field applied parallel to the surface. The normal states of the material also showed something called anomalous Hall signals. This is a sign that the material is behaving in an unusual way. The researchers also found a critical out-of-plane magnetic field of 1. 4 Tesla. This is higher than any other graphene superconductivity. It indicates a strong-coupling superconductivity close to the BCS-BEC crossover. This is a fancy way of saying the material is a good superconductor. This discovery is exciting. It establishes a pure carbon material for the study of topological superconductivity. This could lead to new ways of exploring Majorana modes and topological quantum computing. It's a big step forward in the world of materials science and quantum computing.