Ground state of a quantum critical system: Neutron scattering onCe(Ru1−xFex)2

Magnetic excitations in the spinel compoundLix[Mn1.96Li0.04]Heitmann1, Schmets2, Gaddy3 et al. 2010Phys. Rev. BSelf Cite9040View full textAdd to dashboardCite

“…However, instead of observing that all the magnetic moments evolve with temperature along the lines sketched out in Fig. 1͑a͒ or 1͑b͒, unambiguous evidence 18 for the emergence of magnetic clusters inherent to a percolation network ͓Fig. 1͑c͔͒ was found.…”

“…15͔͒. Montfrooij et al 18 suggested a way out of this apparent contradiction based on the disorder present in a system 19 when it is driven to the QCP by means of chemical substitution. Their arguments are summarized in Fig.…”

“…This was shown in the heavy-fermion compound Ce͑Ru 0.24 Fe 0.76 ͒ 2 Ge 2 . 18 Starting from the heavy-fermion system CeFe 2 Ge 2 , 23 upon increased doping x of Ru on the Fe sites Ce͑Ru 0.24 Fe 0.76 ͒ 2 Ge 2 orders magnetically at 0 K once 1:4 Fe ions have been substituted. 15,24 This isovalent substitution takes place on sites that are not nearest neighbors to the moment carrying Ce sites.…”

Quantum critical fluctuations in the heavy fermion compound Ce(Ni0.935Pd0.065)2Ge2

“…A finite correlation length at a QCP has been observed for Ce(Fe 1−x Ru x ) 2 Ge 2 [16]. Other Ce-122 alloys, such as Ce 1−x La x Ru 2 Si 2 [7], CeRu 2−x Rh x Si 2 [6], and CeCu 2 Si 2 [17] also exhibit finite correlation times.…”

“…Alternatively, Montfrooij [16] has attempted to explain the finite correlation length observed at the QCP in Ce(Fe 1−x Ru x ) 2 Ge 2 in terms of alloy disorder. The underlying idea is that of Kondo disorder.…”