Majorana Crystal in Rhombohedral Graphene

TL;DR

This paper reveals that the intra-valley pairing phase in rhombohedral graphene's superconducting state can be understood as a Majorana crystal on the dual lattice, connecting topological superconductivity with Majorana modes.

Contribution

It demonstrates, through a gauge transformation, that the intra-valley pairing phase corresponds to a Majorana crystal, offering a new perspective on topological superconductivity in rhombohedral graphene.

Findings

Intra-valley pairing phase is equivalent to a Majorana crystal.

The Majorana crystal is formed on the dual honeycomb lattice.

The phase relates to a chiral topological superconductor on the triangular lattice.

Abstract

Recent experiments in rhombohedral graphene report an unusual superconducting phase emerging from a spin- and valley-polarized quarter-metal state. The prevailing interpretation invokes chiral topological superconductivity, but the role of the `Fulde-Ferrell' phase factor due to intra-valley pairing has remained largely unexplored. Here we show, via a gauge transformation, that this phase is equivalent to an ordinary chiral topological superconductor on the triangular lattice, while simultaneously forming an extraordinary Majorana crystal on the dual honeycomb lattice reminiscent of the Haldane model.