Emergent vortex Majorana zero mode in iron-based superconductors

Abstract

The vortex of iron-based superconductors is emerging as a promising platform for Majorana zero mode, owing to a magic integration among intrinsic vortex winding, non-trivial band topology, strong electron-electron correlations, high-Tc superconductivity and the simplification of single material. It overcomes many difficulties suffered in heterostructure-based Majorana platforms, including small topological gap, interfacial contamination, lattice imperfections, and etc. Isolated zero-bias peaks have been found in vortex of several iron-based superconductors. So far, studies from both experimental and theoretical aspects strongly indicate the realization of vortex Majorana zero mode, with a potential to be applied to fault-tolerant quantum computation. By taking Fe(Te,Se) superconductor as an example, here we review the original idea and research progress of Majorana zero modes in this new platform. After introducing the identifications of topological band structure and real zero modes in vortex, we summarize the physics behaviors of vortex Majorana zero modes systematically. First, relying on the behavior of the zero mode wave function and evidence of quasiparticle poisoning, we analyze the mechanism of emergence of vortex Majorana zero modes. Secondly, assisted with some well-established theories, we elaborate the measurements on "Majorana symmetry" and topological nature of vortex Majorana zero modes. After that, we switch from quantum physics to quantum engineering, and analyze the performance of vortex Majorana zero modes under real circumstances, which may potentially benefit the exploration of practical applications in the future. This review follows the physics properties of vortex Majorana zero modes, especially emphasizes the link between phenomena and mechanisms. It provides a chance to bridge the gap between the well-established theories and the newly discovered "iron home" of Majoranas.

Multiple reversals of vortex ratchet effects in a superconducting strip with inclined dynamic pinning landscape*

“…Moreover, when the applied current is large enough in which the Lorentz force dominates, the ratchet effect reaches strongest within a wide range of velocity ν p . The approach could also be useful for the manipulation of vortices in the iron-chalcogenides and the Majorana zero modes in their cores [44][45][46][47] for topological quantum computing. This technique could be used to make something like a quantum computing punch card.…”

Ironing out the details of unconventional superconductivity

“…One of the most recent developments in the field is the discovery of topological properties in some FeSC (for recent reviews, see [17,114,147,148]). As schematically illustrated in Fig.…”

Near zero energy Caroli–de Gennes–Matricon vortex states in the presence of impurities

“…A particular type of Andreev bound state excitations exists on zero-dimensional defects in topological superconductors. These zero energy excitations are known as Majorana zero modes (MZMs) [1][2][3][4][5]. Since these quasiparticles are topologically protected non-Abelian anyons [6][7][8], they can be used to build fault-tolerant qubits [9].…”