A quantum critical point (QCP) occurs upon chemical doping of the weak itinerant ferromagnet Sc 3.1 In . Remarkable for a system with no local moments, the QCP is accompanied by non-Fermi liquid behavior, manifested in the logarithmic divergence of the specific heat both in the ferro-and the paramagnetic states, as well as linear temperature dependence of the low-temperature resistivity. With doping, critical scaling is observed close to the QCP, as the critical exponents δ , γ , and β have weak composition dependence, with δ nearly twice and β almost half of their respective mean-field values. The unusually large paramagnetic moment μ PM ∼ 1.3 μ B / F . U . is nearly composition independent. Evidence for strong spin fluctuations, accompanying the QCP at x c = 0.035 ± 0.005 , may be ascribed to the reduced dimensionality of Sc 3.1 In , associated with the nearly one-dimensional Sc-In chains.
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condensed matter physics
Svanidze, E., L. Liu, B. Frandsen, B. D. White, T. Besara, T. Goko, T. Medina et al. "Non-Fermi liquid behavior close to a quantum critical point in a ferromagnetic state without local moments." Physical Review X 5, no. 1 (2015): 011026.
Physical Review X