Magnetic Excitations of Spin Nematic State in Frustrated Ferromagnetic Chain

TL;DR

This study uses advanced computational techniques to analyze magnetic excitations in a frustrated ferromagnetic chain, revealing distinct gapless and gapped spectra in a spin nematic state under magnetic fields.

Contribution

It provides the first detailed dynamical spin structure factor analysis of a spin nematic phase in a frustrated ferromagnetic chain using density-matrix renormalization group methods.

Findings

Gapless longitudinal and gapped transverse spin excitations identified.

Field-dependent behavior of the excitation gap observed.

Correlation between gapless points and dominant spin correlations established.

Abstract

By exploiting density-matrix renormalization group techniques, we investigate the dynamical spin structure factor of a spin-1/2 Heisenberg chain with ferromagnetic nearest-neighbor and antiferromagnetic next-nearest-neighbor exchange interactions in an applied magnetic field. In a field-induced spin nematic regime, we find gapless longitudinal and gapped transverse spin excitation spectra, in accordance with quasi-long-ranged longitudinal and short-ranged transverse spin correlations, respectively. The gapless point coincides with the dominant longitudinal spin correlation, whereas the gap position exhibits a characteristic field dependence contradicting the dominant transverse spin correlation.