2013/07/04 by Jelena Klinovaja, Peter Stano, Ali Yazdani +1 · 2 citations
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.111.186805
published as Phys. Rev. Lett. 111, 186805 (2013)
arxiv created 2013/07/04 · arxiv updated 2013/11/04
We consider quasi one-dimensional RKKY systems in proximity to an s-wave superconductor. We show that a 2kF-peak in the spin susceptibility of the superconductor in the one-dimensional limit supports helical order of localized magnetic moments via RKKY interaction, where kF is the Fermi wavevector. The magnetic helix is equivalent to a uniform magnetic field and very strong spin-orbit interaction (SOI) with an effective SOI length 1/2kF. We find the conditions to establish such a magnetic state in atomic chains and semiconducting nanowires with magnetic atoms or nuclear spins. Generically, these systems are in a topological phase with Majorana fermions. The inherent self-tuning of the helix to 2kF eliminates the need to tune the chemical potential.