Exact solutions and topological phase diagram in interacting dimerized Kitaev topological superconductors

TL;DR

This paper extends an exactly solvable interacting Kitaev superconductor model by including dimerization, analytically mapping its topological phase diagram with seven phases and identifying critical points with Majorana edge states.

Contribution

It introduces a dimerized version of an exactly solvable interacting Kitaev model and analytically characterizes its complex topological phase diagram.

Findings

Seven distinct topological phases identified.

Presence of Majorana zero-energy edge states in topological phases.

Two tetra-critical points where four phases meet.

Abstract

It was recently shown that an interacting Kitaev topological superconductor model is exactly solvable based on two-step Jordan-Wigner transformations together with one spin rotation. We generalize this model by including the dimerization, which is shown also to be exactly solvable. We analytically determine the topological phase diagram containing seven distinct phases. It is argued that the system is topological when a fermionic many-body Majorana zero-energy edge state emerges. It is intriguing that there are two tetra-critical points, at each of which four distinct phases touch.