Non-Abelian topological superconductivity from melting Abelian fractional Chern insulators

TL;DR

This paper develops a theoretical framework showing how tuning bandwidth in fractional Chern insulators can induce a variety of exotic, including non-Abelian, superconducting phases with potential Majorana zero modes, expanding understanding of topological matter.

Contribution

It introduces a duality-based model explaining how bandwidth tuning transforms fractional Chern insulators into multiple types of superconductors, including non-Abelian ones with Majorana modes.

Findings

Bandwidth tuning drives FCI into five distinct superconductors.

Some superconductors support non-Abelian anyons and Majorana zero modes.

Prediction of higher-charge superconductors with neutral topological order.

Abstract

Fractional Chern insulators (FCI) are exotic phases of matter realized at partial filling of a Chern band that host fractionally charged anyon excitations. Recent numerical studies in several microscopic models reveal that increasing the bandwidth in an FCI can drive a direct transition into a charge-2e superconductor rather than a conventional Fermi liquid. Motivated by this surprising observation, we propose a theoretical framework that captures the intertwinement between superconductivity and fractionalization in a lattice setting. Leveraging the duality between three field-theoretic descriptions of the Jain topological order, we find that bandwidth tuning can drive a single parent FCI at $\nu = 2/3$ into five different superconductors, some of which are intrinsically non-Abelian and support Majorana zero modes. Our results reveal a rich landscape of exotic superconductors with no normal state Fermi surface and predict novel higher-charge superconductors coexisting with neutral non-Abelian topological order at more general filling fractions $\nu = p/(2p+1)$.