title: Topological matter. Observation of Majorana fermions in ferromagnetic atomic chains on a superconductor.
abstract: Majorana fermions are predicted to localize at the edge of a topological superconductor, a state of matter that can form when a ferromagnetic system is placed in proximity to a conventional superconductor with strong spin-orbit interaction. With the goal of realizing a one-dimensional topological superconductor, we have fabricated ferromagnetic iron (Fe) atomic chains on the surface of superconducting lead (Pb). Using high-resolution spectroscopic imaging techniques, we show that the onset of superconductivity, which gaps the electronic density of states in the bulk of the Fe chains, is accompanied by the appearance of zero-energy end-states. This spatially resolved signature provides strong evidence, corroborated by other observations, for the formation of a topological phase and edge-bound Majorana fermions in our atomic chains.
authors.affiliation: Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Stevan
authors.initials: S
authors.lastname: Nadj-Perge
authors.affiliation: Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Ilya K
authors.initials: IK
authors.lastname: Drozdov
authors.affiliation: Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
authors.affiliation: Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Sangjun
authors.initials: S
authors.lastname: Jeon
authors.affiliation: Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Jungpil
authors.initials: J
authors.lastname: Seo
authors.affiliation: Department of Physics, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Allan H
authors.initials: AH
authors.lastname: MacDonald
authors.affiliation: Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA.
authors.forename: B Andrei
authors.initials: BA
authors.lastname: Bernevig
authors.affiliation: Joseph Henry Laboratories and Department of Physics, Princeton University, Princeton, NJ 08544, USA. yazdani@princeton.edu.
authors.forename: Ali
authors.initials: A
authors.lastname: Yazdani