Theory of Raman Scattering in One-Dimensional Quantum Spin-1/2 Antiferromagnets

TL;DR

This paper provides a theoretical analysis of Raman scattering spectra in one-dimensional quantum spin-1/2 antiferromagnets, highlighting their sensitivity to various perturbations and the rich information they reveal about low-energy dynamics.

Contribution

It introduces a detailed theoretical framework for understanding how weak perturbations influence Raman spectra in 1D quantum antiferromagnets, extending beyond higher-dimensional cases.

Findings

Raman spectra are highly sensitive to magnetic anisotropy, longer-range interactions, and bond dimerization.

Different perturbations lead to distinct spectral features as functions of frequency, temperature, and external field.

Raman spectra in 1D systems provide richer information compared to higher-dimensional antiferromagnets.

Abstract

We study theoretically the Raman scattering spectra in the one-dimensional (1D) quantum spin-1/2 antiferromagnets. The analysis reveals that their low-energy dynamics is exquisitely sensitive to various perturbations to the Heisenberg chain with nearest-neighbor exchange interactions, such as magnetic anisotropy, longer-range exchange interactions, and bond dimerization. These weak interactions are mainly responsible for the Raman scattering and give rise to different types of spectra as functions of frequency, temperature, and external field. In contrast to the Raman spectra in higher dimensions in which the two-magnon process is dominant, those in 1D antiferromagnets provide much richer information on these perturbations.