Zero energy Majorana modes in spin ladders and a possible realization of the Kitaev model

Abstract

We show that in double-chain Mott insulators (ladders), disordered alternating ionic potentials may locally destroy coherence of magnetic excitations and lead to the appearance of spontaneously dimerized islands inside the Haldane spin-liquid phase. We argue that a boundary between the dimerized and Haldane phases of a spin-1/2 ladder supports a localized zero-energy Majorana fermion mode. Based on these findings we suggest a realization of a generalized Kitaev model where Majorana fermions can propagate in more than one dimension.

5 pages, 2 figures

References in corpus (3)

• Topological characterization of quantum phase transitions in a S=1/2 spin model
• Topological Majorana and Dirac zero modes in superconducting vortex cores
• Manipulating unpaired Majorana fermions in a quantum spin chain

Cited by in corpus (3)

• Non-perturbative methodologies for low-dimensional strongly-correlated systems: From non-abelian bosonization to truncated spectrum methods
• Majorana fermions in an out-of-equilibrium topological superconducting wire: an exact microscopic transport analysis of a p-wave open chain coupled to normal leads
• Spinful fermionic ladders at incommensurate filling: Phase diagram, local perturbations, and ionic potentials