Fractionalization and topology in amorphous electronic solids

TL;DR

This paper explores how strong interactions affect topological phases in amorphous electronic solids, revealing new correlated and fractionalized states beyond free fermion topologies.

Contribution

It extends topological analysis to strongly interacting amorphous systems using a parton approach, uncovering novel Mott insulators and fractionalized phases.

Findings

Identification of amorphous Mott insulators with chiral edge modes

Discovery of fractionalized Anderson insulating phase

Mapping of the interacting phase diagram in amorphous networks

Abstract

Band-topology is traditionally analyzed in terms of gauge-invariant observables associated with crystalline Bloch wavefunctions. Recent work has demonstrated that many of the free fermion topological characteristics survive even in an amorphous setting. In this work, we extend these studies to incorporate the effect of strong repulsive interactions on the fate of topology and other correlation induced phenomena. Using a parton-based approach, we obtain the interacting phase diagram for an electronic two-orbital model with tunable topology in a two dimensional amorphous network. In addition to the (non-)topological phases that are adiabatically connected to the free fermion limit, we find a number of strongly interacting amorphous analogs of crystalline Mott insulating phases with non-trivial chiral neutral edge modes, and a fractionalized Anderson insulating phase. The amorphous networks thus provide a new playground for studying a plethora of exotic states of matter, and their glassy dynamics, due to the combined effects of non-trivial topology, disorder, and strong interactions.