Researchers from Korea's Daegu Gyeongbuk Institute of Science and Technology (DGIST), Pohang University of Science and Technology, Institute for Basic Science, KAIST, Japan's National Institute for Materials Science and Max Planck Institute for Solid State Research in Germany have observed a unique quantum state in twisted bi-layer graphene.
This research provides insights into a quantum state that challenges the limitations of conventional semiconductor technology, broadening the horizon for quantum advancements and offering new avenues for technological innovation.
The researchers explored a structure made of two graphene layers slightly twisted relative to each other, creating a new quantum state. This configuration is comparable to overlapping two transparent films with regular patterns; when slightly rotated, the patterns combine to produce entirely new ones.
The team found that these unique patterns give rise to new electron dynamics. Specifically, the rules governing electron movement are transformed—electrons cannot cross between layers, yet they experience strong Coulomb interactions that significantly influence their behavior.
One of the most notable findings was the identification of a novel electronic state termed the “1/3 fractional quantum Hall state.” In this state, electrons move in a manner suggesting they are divided into three distinct parts—a sharp departure from their conventional behavior. This phenomenon stems from the strong mutual interactions between electrons as they interact across the twisted graphene layers. Using Monte Carlo simulations, the researchers theoretically validated this state and explored its profound physical implications.
Professor Gilyoung Cho of KAIST highlighted the importance of the discovery, stating, “Our identification of a fractional quantum Hall state in novel materials could play a pivotal role in advancing quantum computing technologies.”
Professor Youngwook Kim of DGIST underscored the collaborative nature of the research: “We relied on high-magnetic-field experimental equipment from the Max Planck Society to obtain crucial data, and this international partnership has opened exciting new possibilities,” he said.
Looking ahead, Professor Kim expressed his hope to replicate similar conditions without relying on magnetic fields, further expanding the scope of their research. This work signifies a major step toward realizing quantum technologies that were once thought to be unattainable, with potential applications spanning quantum memory, computing, and beyond.
