STICLET, Doru; SEABRA, Luis; POLLMANN, Frank; CAYSSOL, Jérôme

doi:10.1103/PhysRevB.89.115430

Métadonnées

Licence d’utilisation du document

http://creativecommons.org/licenses/by-nc/

STICLET, Doru
Laboratoire Ondes et Matière d'Aquitaine [LOMA]
Max-Planck-Institut für Physik komplexer Systeme [MPI-PKS]

SEABRA, Luis
Max-Planck-Institut für Physik komplexer Systeme [MPI-PKS]
Department of Physics [Haifa]

POLLMANN, Frank
Max-Planck-Institut für Physik komplexer Systeme [MPI-PKS]

Langue

Article de revue

Ce document a été publié dans

Physical Review B: Condensed Matter and Materials Physics (1998-2015). 2014-03-24, vol. 89, n° 11, p. 115430 (1-18)

American Physical Society

Résumé en anglais

We consider one-dimensional topological insulators hosting fractionally charged midgap states in the presence and absence of induced superconductivity pairing. Under the protection of a discrete symmetry, relating positive and negative energy states, the solitonic midgap states remain pinned at zero energy when superconducting correlations are induced by proximity effect. When the superconducting pairing dominates the initial insulating gap, Majorana fermion phases develop for a class of insulators. As a concrete example, we study the Creutz model with induced s-wave superconductivity and repulsive Hubbard-type interactions. For a finite wire, without interactions, the solitonic modes originating from the nonsuperconducting model survive at zero energy, revealing a fourfold-degenerate ground state. However, interactions break the aforementioned discrete symmetry and completely remove this degeneracy, thereby producing a unique ground state which is characterized by a topological bulk invariant with respect to the product of fermion parity and bond inversion. In contrast, the Majorana edge modes are globally robust to interactions. Moreover, the parameter range for which a topological Majorana phase is stabilized expands when increasing the repulsive Hubbard interaction. The topological phase diagram of the interacting model is obtained using a combination of mean-field theory and density matrix renormalization group techniques.< Réduire

Mots clés en anglais

Lattice fermion models

Phases: geometric dynamic or topological

Other inorganic compounds

DOI

http://dx.doi.org/10.1103/PhysRevB.89.115430

Projet Européen

TOPOLOGICAL EFFECTS IN MATTER WITH STRONG SPIN-ORBIT COUPLING

Project ANR

Etats de Majorana et d'Andreev dans des circuits hybrides combinant des matériaux magnétiques et supraconducteurs - ANR-12-BS04-0016
Transport électronique dans les isolants topologiques - ANR-10-BLAN-0419

Origine

Importé de hal

Unités de recherche

Laboratoire Ondes et Matière d'Aquitaine (LOMA) - UMR 5798