The resonant state at filling factor {\nu} = 1/2 in chiral fermionic ladders

TL;DR

This paper investigates the properties of a helical state at filling factor 1/2 in chiral fermionic ladders, revealing a fractional quantum Hall-like state in a 1D system with entanglement and correlation analysis.

Contribution

It characterizes a novel helical state at filling 1/2 in chiral fermionic ladders, linking it to fractional quantum Hall physics in a 1D limit.

Findings

Identification of a gap in the spin sector leading to the helical state

Analysis of entanglement properties and correlation functions of the state

Development of techniques applicable to similar quasi-1D systems

Abstract

Helical liquids have been experimentally detected in both nanowires and ultracold atomic chains as the result of strong spin-orbit interactions. In both cases the inner degrees of freedom can be considered as an additional space dimension, providing an interpretation of these systems as synthetic ladders, with artificial magnetic fluxes determined by the spin-orbit terms. In this work, we characterize the helical state which appears at filling $\nu=1/2$: this state is generated by a gap arising in the spin sector of the corresponding Luttinger liquid and it can be interpreted as the one-dimensional (1D) limit of a fractional quantum Hall state of bosonic pairs of fermions. We study its main features, focusing on entanglement properties and correlation functions. The techniques developed here provide a key example for the study of similar quasi-1D systems beyond the semiclassical approximation commonly adopted in the description of the Laughlin-like states.