Fractional topological states of dipolar fermions in one-dimensional optical superlattices

TL;DR

This paper demonstrates the existence of fractional topological states in dipolar fermions within one-dimensional optical superlattices, revealing connections to fractional quantum Hall states and suggesting experimental realization in cold atomic systems.

Contribution

It uncovers fractional topological states in 1D dipolar fermions and links them to fractional quantum Hall phenomena, a novel insight in low-dimensional topological physics.

Findings

Fractional topological states with p-fold degeneracy at filling factor =1/p.

Quasihole excitations follow fractional quantum Hall counting rules.

Total Chern number of degenerate states is a nonzero integer.

Abstract

We study the properties of dipolar fermions trapped in one-dimensional bichromatic optical lattices and show the existence of fractional topological states in the presence of strong dipole-dipole interactions. We find some interesting connections between fractional topological states in one-dimensional superlattices and the fractional quantum Hall states: (i) the one-dimensional fractional topological states for systems at filling factor \nu=1/p have p-fold degeneracy, (ii) the quasihole excitations fulfill the same counting rule as that of fractional quantum Hall states, and (iii) the total Chern number of p-fold degenerate states is a nonzero integer. The existence of crystalline order in our system is also consistent with the thin-torus limit of the fractional quantum Hall state on a torus. The possible experimental realization in cold atomic systems offers a new platform for the study of fractional topological phases in one-dimensional superlattice systems.