Electric-Field Induced Majorana Fermions in Armchair Carbon Nanotubes

Understand

We consider theoretically an armchair Carbon nanotube (CNT) in the presence of an electric field and in contact with an s-wave superconductor.

• We show that the proximity effect opens up superconducting gaps in the CNT of different strengths for the exterior and interior branches of the two Dirac points.
• For strong proximity induced superconductivity the interior gap can be of the p-wave type, while the exterior gap can be tuned by the electric field to be of the s-wave type.
• Such a setup supports a single Majorana bound state at each end of the CNT.