Fractional Chern insulator edges: crystalline effects and optical measurements

TL;DR

This paper investigates the edge states of fractional Chern insulators, analyzing how lattice effects cause deviations from idealized models, and proposes experimental methods to measure these effects in various physical systems.

Contribution

It provides a detailed analysis of lattice-induced deviations in FCI edge states and suggests experimental techniques for their observation.

Findings

Quantified deviations from hydrodynamic limit due to lattice effects.

Disentangled universal and nonuniversal edge properties.

Proposed time-resolved edge spectroscopy for experimental access.

Abstract

Edge states of chiral topologically ordered phases are commonly described by chiral Luttinger liquids, effective theories that are exact only in the hydrodynamic limit. Motivated by recent bulk observations of fractional Chern insulators (FCIs) in two-dimensional materials and by synthetic realizations in ultracold atoms, we revisit this framework and quantify deviations from the hydrodynamic limit due to lattice effects. Using a combination of analytical arguments and numerical simulations, we disentangle universal from nonuniversal edge properties. We outline experimental probes in excitonic FCIs and in ultracold atom systems, and in particular propose time-resolved edge spectroscopy to directly access the predicted exponents and velocities.