Magnetic Excitations in U(Ru_{1-x}Rh_x)_2Si_2 (x<=0.03)

TL;DR

This study uses inelastic neutron scattering to examine how magnetic excitations evolve in U(Ru_{1-x}Rh_x)_2Si_2 as it transitions from hidden order to antiferromagnetic phases, revealing the suppression of HO-related excitations in the AF phase.

Contribution

It provides the first detailed analysis of magnetic excitations across the HO to AF transition in Rh-doped URu2Si2, highlighting the disappearance of HO excitations in the AF phase.

Findings

Inelastic peaks at specific Q vectors are reduced in AF-dominant compositions.

Magnetic excitations associated with hidden order vanish in the antiferromagnetic phase.

The transition region shows a strong correlation between magnetic excitations and phase dominance.

Abstract

We have investigated magnetic excitations for a mixed phase of hidden order (HO) and the antiferromagnetic (AF) order in U(Ru_{1-x}Rh_x)_2Si_2 (x <= 0.03) by means of inelastic neutron scattering. The inelastic peaks observed at Q=(1,0,0) and (1,0.4,0) in the HO phase for x=0 and 0.015 at 1.4 K are found to be strongly reduced in the AF dominant compositions of x=0.02 and 0.03. Similar behavior is observed as the HO is replaced by the AF order upon cooling for x=0.02. The x-T region in which the strong reduction of inelastic peaks is observed corresponds to the AF-rich region, indicating that the magnetic excitations typical for the HO-phase vanish in the AF phase.