Anomalous scaling behavior of the dynamical spin susceptibility of Ce${}_{0.925}$La${}_{0.075}$Ru${}_2$Si${}_2$

Abstract

Inelastic neutron scattering measurements have been performed on single crystals of the heavy fermion compound Ce${}_{0.925}$La${}_{0.075}$Ru${}_2$Si${}_2$ in broad energy [0.1, 9.5 meV] and temperature [40 mK, 294 K] ranges in order to address the question of scaling behavior of the dynamical spin susceptibility at the quantum critical point of an itinerant magnetic system. For two wavevectors $\mathbf{Q}$ corresponding to uncorrelated and antiferromagnetically correlated spin fluctuations, it is found that the dynamical spin susceptibility ${\chi }^{\prime \prime }(\mathbf{Q},E,T)$ is independent of temperature below a cut-off temperature $T_{\mathbf{Q}}$: the spin fluctuation amplitude saturates at low temperatures contrarily to its expected divergence at a quantum critical point. Above $T_{\mathbf{Q}}$, a $\mathbf{Q}$-dependent scaling behavior of the form $T{\chi }^{\prime \prime }(\mathbf{Q},E,T)=C_{\mathbf{Q}}f[E/(a_{\mathbf{Q}}{T}^{{\beta }_{\mathbf{Q}}})]$ with ${\beta }_{\mathbf{Q}}<1$ is obtained. This scaling does not enter the general framework of quantum phase transition theories, since it is obtained in a high temperature range, where Kondo spin fluctuations depend strongly on temperature.

8 pages, 6 figures

References in corpus (3)

• Spin Fluctuation in Heavy Fermion CeRu_2Si_2
• Spin Fluctuations and Non-Fermi-Liquid Behavior of CeNi_2Ge_2
• Novel dynamic scaling regime in hole-doped La2CuO4

Cited by in corpus (3)

• Quantum Critical Point of Itinerant Antiferromagnet in Heavy Fermion
• Artificial scaling laws of the dynamical magnetic susceptibility in heavy-fermion systems
• Low energy spin fluctuations in the heavy fermion compound Ce${}_{0.925}$La${}_{0.075}$Ru${}_2$Si${}_2$