Chiral superconductivity in a semiconducting wire induced by helical magnetic order

TL;DR

This paper demonstrates that a one-dimensional semiconductor coupled with a superconductor and a helical magnet can host chiral superconductivity and Majorana zero modes without external magnetic fields or intrinsic spin-orbit coupling.

Contribution

It introduces a novel heterostructure setup that enables topological superconductivity through magnetic order and proximity effects, bypassing traditional requirements.

Findings

Chiral superconductivity can be realized without external magnetic fields.

Majorana zero modes appear at the ends of the heterostructure.

The topological regime is tunable via chemical potential and magnetic interactions.

Abstract

Chiral superconductors are sought after for their promising but elusive Majorana zero modes. We show that a one-dimensional semiconductor in proximity to a conventional superconductor and a helical magnet can exhibit chiral superconductivity, without the need for external magnetic fields or intrinsic spin-orbit coupling. The effective proximity-induced gap and the triplet gap arising from magnon fluctuations can be made to interfere constructively. The heterostructure can be tuned into a topological regime with Majorana zero modes at its ends, over a range of chemical potentials proportional to the spin-electron coupling.