Fermion Fractionalization to Majorana Fermions in Dimerized Kitaev Superconductor

TL;DR

This paper theoretically investigates a one-dimensional dimerized Kitaev superconductor model, revealing how electron fractionalization into Majorana fermions occurs at solitons, with detailed analysis of phase diagrams, bound states, and conductance.

Contribution

It introduces two types of topological numbers based on different symmetries, providing new insights into the interference between sublattice symmetry and superconductivity.

Findings

Electron fractionalization to Majorana fermions at solitons.

Identification of two topological numbers related to different symmetries.

Analysis of phase diagram, zero-energy states, and conductance features.

Abstract

We study theoretically a one-dimensional dimerized Kitaev superconductor model which belongs to BDI class with time-reversal, particle-hole, and chiral symmetries. There are two sources of the particle-hole symmetry, i.e., the sublattice symmetry and superconductivity. Accordingly, we define two types of topological numbers with respect to the chiral indices of normal and Majorana fermions, which offers an ideal laboratory to examine the interference between the two different physics within the same symmetry class. Phase diagram, zero-energy bound states, and conductance at normal metal/superconductor junction of this model are unveiled from this viewpoint. Especially, the electron fractionalization to the Majorana fermions showing the splitting of the local density of states is realized at the soliton of the dimerization in this model.