Resonant Two-Magnon Raman Scattering in Cuprate Antiferromagnetic Insulators

TL;DR

This study investigates two-magnon Raman scattering in cuprate antiferromagnetic insulators, revealing complex spectral features and excitation energy dependence, and analyzes the data to extract magnetic and electronic parameters.

Contribution

It applies the triple resonance theory to experimental data, providing new insights into magnetic interactions and band parameters in cuprate insulators.

Findings

Revealed composite structure of the two-magnon line shape

Discovered strong nonmonotonic dependence of scattering intensity on excitation energy

Deduced magnetic interaction and band parameters from resonance profiles

Abstract

We present results of low-temperature two-magnon resonance Raman excitation profile measurements for single layer Sr_2CuO_2Cl_2 and bilayer YBa_2Cu_3O_{6 + \delta} antiferromagnets over the excitation region from 1.65 to 3.05 eV. These data reveal composite structure of the two-magnon line shape and strong nonmonotic dependence of the scattering intensity on excitation energy. We analyze these data using the triple resonance theory of Chubukov and Frenkel (Phys. Rev. Lett., 74, 3057 (1995)) and deduce information about magnetic interaction and band parameters in these materials.