An international team of researchers, led by the University of Manchester, has achieved robust superconductivity in high magnetic fields using a newly created one-dimensional system. Achieving superconductivity in the quantum Hall regime has been a longstanding challenge, which this recent work aimed to address.
The team followed the conventional route where counterpropagating edge states were brought into close proximity to each other. However, this approach was found to be limited. “Our initial experiments were primarily motivated by the strong persistent interest in proximity superconductivity induced along quantum Hall edge states,” explained University of Mnchester's Dr. Barrier, the paper’s lead author. “This possibility has led to numerous theoretical predictions regarding the emergence of new particles known as non-abelian anyons.”
The team then explored a new strategy inspired by an earlier work that showed that the boundaries between domains in graphene could be highly conductive.
The team placed the domain walls between two superconductors to achieve the desired ultimate proximity between counterpropagating edge states while minimizing the disorder’s effects.
The investigation reportedly revealed that proximity superconductivity does not originate from the quantum Hall edge states propagating along domain walls. Instead, it comes from the strictly 1D electronic states existing within the domain walls themselves. These 1D states exhibited a greater ability to hybridize with superconductivity compared to quantum Hall edge states. The 1D nature of the interior states is responsible for the observed robust supercurrents at high magnetic fields.
The discovery of single-mode 1D superconductivity could lead to exciting avenues for further research.
“In our devices, electrons propagate in two opposite directions within the same nanoscale space and without scattering,” Dr. Barrier said. “Such 1D systems are exceptionally rare and hold promise for addressing a wide range of problems in fundamental physics.”
The team has already showcased the ability to manipulate these electronic states using gate voltage.
“It is fascinating to think what this novel system can bring us in the future. The 1D superconductivity presents an alternative path towards realizing topological quasiparticles combining the quantum Hall effect and superconductivity,” concluded the team.
The development of the new 1D superconductor could pave the way for quantum technology advancements and further exploration of new physics.