Topological superconductivity in carbon nanotubes with a small magnetic flux

Abstract

We show that a one-dimensional topological superconductor can be realized in carbon nanotubes, using a relatively small magnetic field. Our analysis relies on the intrinsic curvature-enhanced spin-orbit coupling of the nanotubes, as well as on the orbital effect of a magnetic flux threaded through the nanotube. Tuning experimental parameters, we show that a half-metallic state may be induced in the nanotube. Coupling the system to an Ising superconductor, with an appreciable spin-triplet component, can then drive the nanotube into a topological superconducting phase. The proposed scheme is investigated by means of real-space tight-binding simulations, accompanied by an effective continuum low-energy theory, which allows us to gain some insight on the roles of different terms in the Hamiltonian. We calculate the topological phase diagram and ascertain the existence of localized Majorana zero modes near the edges. Moreover, we find that in the absence of a magnetic field, a regime exists where sufficiently strong interactions drive the system into a time-reversal-invariant topological superconducting phase.

11 pages, 7 figures

References in corpus (10)

• Non-Abelian Anyons and Topological Quantum Computation
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• Observation of Majorana Fermions in a Nb-InSb Nanowire-Nb Hybrid Quantum Device
• Majorana bound states in a coupled quantum-dot hybrid-nanowire system
• Spin-orbit coupling in curved graphene, fullerenes, nanotubes, and nanotube caps
• Coupling of Spin and Orbital Motion of Electrons in Carbon Nanotubes
• Search for Majorana fermions in multiband semiconducting nanowires
• Strong localization of Majorana end states in chains of magnetic adatoms

Cited by in corpus (11)

• Magnetic field-induced "mirage" gap in an Ising superconductor
• Phase-induced topological superconductivity in a planar heterostructure
• Three-phase Majorana zero modes at tiny magnetic fields
• One-dimensional topological superconductivity based entirely on phase control
• Majorana zero modes induced by superconducting phase bias
• Majorana braiding gates for topological superconductors in a one dimensional geometry
• Nanoassembly technique of carbon nanotubes for hybrid circuit-QED
• Topological superconductivity in a magnetic-texture coupled Josephson junction
• Supercurrent and phase slips in a ballistic carbon nanotube embedded into a van der Waals heterostructure
• Magnetic flux induced topological superconductivity in magnetic atomic rings
• Nonlocal signatures of hybridization between quantum dot and Andreev bound states