Chiral spin states in polarized kagome spin systems with spin-orbit coupling

TL;DR

This paper investigates how geometric frustration, spin-orbit coupling, and ferromagnetism in kagome spin systems can lead to chiral spin states that resemble fractional quantum Hall states for bosons, with high energy scales.

Contribution

It proposes that kagome spin systems with combined effects can host bosonic FQH states, highlighting a new class of high-energy chiral spin states.

Findings

Chiral spin states are likely in polarized kagome systems with spin-orbit coupling.

The energy scale of these states is comparable to spin-orbit coupling and ferromagnetism.

Such states are much higher in energy than traditional FQH states in semiconductors.

Abstract

We study quantum spin systems with a proper combination of geometric frustration, spin-orbit coupling and ferromagnetism. We argue that such a system is likely to be in a chiral spin state, a fractional quantum Hall (FQH) state for bosonic spin degrees of freedom. The energy scale of the bosonic FQH state is of the same order as the spin-orbit coupling and ferromagnetism --- overall much higher than the energy scale of FQH states in semiconductors.