Engineering Majorana Kramers Pairs In Synthetic High Spin Chern Insulators

TL;DR

This paper proposes a method to realize Majorana Kramers pairs in synthetic high spin Chern insulators by exploiting electron interactions and phase transitions, with potential implementation in cold-atom systems.

Contribution

It introduces a novel scheme for engineering Majorana Kramers pairs via interaction-driven phase control in high spin topological insulators, connecting superconducting and spin-density wave phases.

Findings

Identification of multiple interaction-driven phases including helical Luttinger liquids and spin density waves.

Demonstration that Majorana Kramers pairs can be stabilized at phase interfaces.

Proposal for realizing these phenomena in cold-atom platforms.

Abstract

High spin-Chern-number topological phases provide a promising low-dimensional platform for realizing double-helical edge states. In this letter, we show how these edge states can host a variety of phases driven by electron interaction effects, including multi-channel helical Luttinger liquid, spin density wave, superconducting phases, and a new type of $\pi$-junction analog of the latter two, where the transitions between the phases can be controlled. The superconducting phase in the interacting system is shown to be adiabatically connected to a time-reversal-symmetric topological superconductor in the non-interacting DIII class. This connection stabilizes Majorana Kramers pairs as domain wall states at the interface between the superconducting and $\pi$-spin-density wave phases, with the latter exhibiting a time-reversal-symmetric spin-density wave phase. We discuss the possibility of realizing our proposed scheme for generating Majorana Kramers pairs in a cold-atom based platform with existing techniques, and how it could offer potential advantages over other approaches.