Change of Antiferromagnetic Structure near a Quantum Critical Point in CeRh1-xCoxIn5

TL;DR

This study investigates how antiferromagnetic structures in CeRh_{1-x}Co_xIn_5 evolve near a quantum critical point, revealing the emergence and suppression of different magnetic orders with Co doping, which may relate to superconductivity.

Contribution

It provides detailed neutron scattering data showing the evolution of AF orders near the QCP in CeRh_{1-x}Co_xIn_5, highlighting new magnetic phases and their potential link to superconductivity.

Findings

Incommensurate AF order weakly suppressed by Co doping

Emergence of commensurate and incommensurate AF structures at intermediate x

Suppression of the q_h AF order near x=0.7

Abstract

The elastic neutron scattering experiments were carried out on the solid solutions CeRh_{1-x}Co_xIn_5 to clarify the nature of the antiferromagnetic (AF) state in the vicinity of the quantum critical point (QCP): x_c ~0.8. The incommensurate AF order with the wave vector of q_h=(1/2,1/2,~0.3) observed in pure CeRhIn_5 is weakly suppressed upon doping with Co, and a commensurate q_c=(1/2,1/2,1/2) and an incommensurate q_1=(1/2,1/2,~0.42) AF structures evolve at intermediate Co concentrations. These AF orders are enhanced at x=0.7, and furthermore the q_h AF order vanishes. These results suggest that the AF correlations with the q_c and q_1 modulations are significantly enhanced in the intermediate x range, and may be connected with the evolution of the superconductivity observed above x~0.3.