Imagine a world where electricity flows without resistance, where cutting-edge quantum states hold the key to stable and efficient quantum computers. This vision is now one step closer to reality, thanks to a team of experimental physicists at the University of Cologne. They have demonstrated the creation of superconducting effects in materials with unique edge-only electrical properties. Their study, titled ‘Induced superconducting correlations in a quantum anomalous Hall insulator’, represents a significant milestone in the field of quantum materials.

The quantum anomalous Hall effect and superconductivity are two phenomena that have captured the imagination of scientists for decades. While superconductivity allows electricity to flow without resistance, the quantum anomalous Hall effect, with its zero resistance confined to edges, adds a fascinating twist. The synergy of these two phenomena is predicted to give rise to Majorana fermions – topologically-protected particles that could revolutionize quantum computing. By inducing superconductivity in the edges of a quantum anomalous Hall insulator, researchers have successfully created chiral Majorana edge states, paving the way for ‘flying qubits’ that are both efficient and protected.

Anjana Uday, a final-year doctoral researcher at the University of Cologne, shared her excitement about the team’s achievement: “After five years of hard work, we were able to induce chiral Majorana states at the edges of thin films of the quantum anomalous Hall insulator. This breakthrough, known as crossed Andreev reflection, allows us to detect the induced superconductivity in the topological edge state.”

Collaborating with experts from KU Leuven, the University of Basel, and Forschungszentrum Jülich, the Cologne group received vital support in theoretical research within the Cluster of Excellence Matter and Light for Quantum Computing (ML4Q). Professor Yoichi Ando, the spokesperson for ML4Q, emphasized the significance of this collaborative effort in propelling the research forward.

This discovery opens up a plethora of possibilities for future research. The next steps involve confirming the existence of chiral Majorana fermions and exploring their exotic properties. By harnessing topological superconductivity and chiral Majorana edge states, quantum computing could be revolutionized, offering stable qubits that are resilient to decoherence. This study paves the way for more robust and scalable quantum computers, bringing us closer to a future where quantum technology reshapes our world.