Science & Technology, UK (Commonwealth Union) – Superconductivity is a phenomenon that has captivated the imagination of scientists and engineers alike since its discovery over a century ago. From its humble beginnings to its transformative potential in modern technology, the journey of superconductivity has been one of curiosity, discovery, and innovation.
At its core, superconductivity defies conventional wisdom. It occurs when certain materials, cooled to extremely low temperatures, suddenly lose all electrical resistance, allowing for the uninterrupted flow of current. This remarkable property, first observed in mercury by Dutch physicist Heike Kamerlingh Onnes in 1911, opened the door to a realm of possibilities previously unimaginable.
A significant breakthrough in superconductivity has been achieved by researchers at The University of Manchester, marking a notable advancement in condensed matter physics. They’ve achieved robust superconductivity in high magnetic fields using a newly developed one-dimensional (1D) system. This breakthrough paves the way for achieving superconductivity in the quantum Hall regime, a long-standing obstacle in the field.
Superconductivity, which enables certain materials to conduct electricity without resistance, holds immense potential for advancing quantum technologies. However, attaining superconductivity in the quantum Hall regime, characterized by quantized electrical conductance, has proven to be exceptionally difficult.
Published recently in Nature in the April edition, the research outlines the extensive efforts of the Manchester team, led by Professor Andre Geim along with Dr. Julien Barrier and Dr. Na Xin, in achieving superconductivity in the quantum Hall regime. Initially, they pursued the conventional approach of bringing counterpropagating edge states into close proximity. However, this method had its limitations, according to the researchers of the study.
Dr. Barrier, the lead author of the paper, elucidates that their initial experiments were driven by the persistent interest in inducing proximity superconductivity along quantum Hall edge states. This prospect has spurred numerous theoretical predictions regarding the emergence of novel particles, such as non-abelian anyons.”
The team embarked on a new approach inspired by their prior research showcasing the remarkable conductivity of boundaries within graphene domains. By inserting these domain walls between two superconductors, they achieved optimal proximity between counterpropagating edge states while minimizing disorder effects.
Dr. Barrier indicated that they were pleasantly surprised to witness significant supercurrents at relatively mild temperatures, reaching up to one Kelvin in every device we produced.
While conducting more examinations they unveiled that the superconductivity proximity originated not from quantum Hall edge states along domain walls, but rather from strictly one-dimensional electronic states within the walls themselves. These one-dimensional states, validated by Professor Vladimir Fal’ko’s theory group at the National Graphene Institute, displayed a stronger ability to intertwine with superconductivity compared to quantum Hall edge states. The inherent one-dimensional nature of these interior states is believed to underpin the robust supercurrents observed even under high magnetic fields.
The finding of the single-mode 1D superconductivity demonstrated an exciting pathway for extending the research. “In our devices, electrons propagate in two opposite directions within the same nanoscale space and without scattering”, explained Dr Barrier. “Such 1D systems are exceptionally rare and hold promise for addressing a wide range of problems in fundamental physics.”
The team has already showcased their capability to manipulate these electronic states through gate voltage manipulation, enabling the observation of standing electron waves that influence the superconducting properties.
“It is fascinating to think what this novel system can bring us in the future. The 1D superconductivity presents an alternative path towards realising topological quasiparticles combining the quantum Hall effect and superconductivity,” added Dr Xin. This is just one example of the vast potential our findings holds.”
Two decades following the emergence of graphene, this study from The University of Manchester marks yet another stride in superconductivity. The unveiling of this innovative 1-Dimensional superconductor promises to unlock avenues for quantum technological progress and foster deeper investigations into novel physics, garnering attention from diverse scientific circles.
The National Graphene Institute (NGI) stands as a global pioneer in graphene and 2D material exploration, dedicated to fundamental research. Nestled within The University of Manchester, the birthplace of graphene in 2004 by Professors Sir Andre Geim and Sir Kostya Novoselov, it serves as a hub for top-tier experts in the field. Here, a vibrant community of research specialists tirelessly pursues groundbreaking discoveries. The latest findings by the researchers are likely to further enhance the field.
