This title appears in the Scientific Report : 2019 

Relaxing Kondo-screened Kramers doublets in CeRhSi 3
Pásztorová, J. (Corresponding author)
Howell, A. / Songvilay, M. / Sarte, P. M. / Rodriguez-Rivera, J. A. / Arévalo-López, A. M. / Schmalzl, K. / Schneidewind, A. / Dunsiger, S. R. / Singh, D. K. / Petrovic, C. / Hu, R. / Stock, C.
Streumethoden; JCNS-2
Streumethoden; PGI-4
Physical review / B covering condensed matter and materials physics, 99 (2019) 12, S. 125144
Woodbury, NY 2019
Journal Article
Jülich Centre for Neutron Research (JCNS)
Materials and Processes for Energy and Transport Technologies
Quantum Condensed Matter: Magnetism, Superconductivity
Controlling Collective States
Controlling Collective States
Please use the identifier: in citations.
Please use the identifier: in citations.
CeRhSi3 is a superconductor under pressure coexisting with a weakly antiferromagnetic phase characterized by a Bragg peak at →q0=(∼0.2,0,0.5) [N. Aso et al., J. Magn. Magn. Mater. 310, 602 (2007)]. The compound is also a heavy-fermion material with a large specific heat coefficient γ=110 mJ mol−1K−2 and a high Kondo temperature of TK=50 K, indicating CeRhSi3 is in a strongly Kondo screened state. We apply high-resolution neutron spectroscopy to investigate the magnetic fluctuations in the normal phase, at ambient pressures, and at low temperatures. We measure a commensurate dynamic response centered around the →Q=(0,0,2) position that gradually evolves to H∼0.2 with decreasing temperature and/or energy transfers. The response is broadened both in momentum and energy and is not reminiscent of sharp spin wave excitations found in insulating magnets where the electrons are localized. We parametrize the excitation spectrum and temperature dependence using a heuristic model utilizing the random-phase approximation to couple relaxing Ce3+ ground-state Kramers doublets with a Kondo-like dynamic response. With a Ruderman-Kittel-Kasuya-Yosida exchange interaction within the ab plane and an increasing single-site susceptibility, we can qualitatively reproduce the neutron spectroscopic results in CeRhSi3 and, namely, the trade-off between scattering at commensurate and incommensurate positions. We suggest that the antiferromagnetic phase in CeRhSi3 is driven by weakly correlated relaxing localized Kramers doublets and that CeRhSi3 at ambient pressures is on the border between a Rudderman-Kittel-Yosida antiferromagnetic state and a Kondo-screened phase where static magnetism is predominately absent.