Chiral order and electromagnetic dynamics in one-dimensional multiferroic cuprates

TL;DR

This paper demonstrates how ferromagnetic interactions stabilize chiral magnetic order in one-dimensional multiferroic cuprates, explaining experimental electromagnon phenomena through numerical and semi-classical analyses.

Contribution

It reveals the stabilizing role of ferromagnetic exchange in chiral order and clarifies the magnetic structure and electromagnon origins in LiCu2O2.

Findings

Ferromagnetic exchange stabilizes vector spin chiral order.

Semi-classical analysis resolves magnetic structure controversies.

Identifies pseudo-Nambu-Goldstone modes as electromagnon origin.

Abstract

We show by unbiased numerical calculations that the ferromagnetic nearest-neighbor exchange interaction stabilizes a vector spin chiral order against the quantum fluctuation in a frustrated spin-1/2 chain relevant to multiferroic cuprates, LiCu2O2 and LiCuVO4. Our realistic semi-classical analyses for LiCu2O2 resolve controversies on the helical magnetic structure and unveil the pseudo-Nambu-Goldstone modes as the origin of experimentally observed electromagnons.