Longitudinal magnetic excitation in KCuCl3 studied by Raman scattering under hydrostatic pressures

TL;DR

This study investigates how hydrostatic pressure affects magnetic excitations in KCuCl3 using Raman scattering, revealing a pressure-dependent longitudinal magnetic mode linked to quantum phase transitions.

Contribution

It provides the first detailed Raman scattering analysis of longitudinal magnetic excitations in KCuCl3 under high pressure, highlighting the pressure dependence of these modes.

Findings

Observation of a pressure-induced one-magnon Raman peak

Pressure dependence of mode frequency, width, and intensity

Identification of longitudinal magnetic excitation in quantum phase

Abstract

We measure Raman scattering in an interacting spin-dimer system KCuCl3 under hydrostatic pressures up to 5 GPa mediated by He gas. In the pressure-induced quantum phase, we observe a one-magnon Raman peak, which originates from the longitudinal magnetic excitationand is observable through the second-order exchange interaction Raman process. We report the pressure dependence of the frequency, halfwidth and Raman intensity of this mode.