Non-Fermi liquid behavior of the electrical resistivity at the ferromagnetic quantum critical point (original) (raw)

Quantum Critical Ferromagnetism in NixPd1- x Alloys

Journal of Low Temperature Physics, 2004

We analyze the non-Fermi liquid behavior in the proximity of the quantum phase transition induced by the strong polarization of the electrons due to local magnetic moments in NixPd1-x alloys. We use the renormalization group approach introduced by Hertz–Mi11is–Moriya (HMM) to estimate the temperature dependence of the electrical resistivity for the case of three dimensional itinerant ferromagnets. We study two

Non-Fermi Behavior Near Ferromagnetic Quantum Phase Transition

Journal of Superconductivity - J SUPERCOND, 2001

We propose a model for the explanation of the non-Fermi behavior near the ferromagnetic quantum phase transition. The scaling equations have been used to calculate the specific heat and we showed that the quantum effects are responsible for the T ln T term from the specific heat. The results are in agreement with recent experimental data obtained in the NixPd1 - x system. The relation with the other approaches was also discussed.

Resistivity of a Non-Galilean–Invariant Fermi Liquid near Pomeranchuk Quantum Criticality

Physical Review Letters, 2011

We analyze the effect of the electron-electron interaction on the resistivity of a metal near a Pomeranchuk quantum phase transition (QPT). We show that Umklapp processes are not effective near a QPT, and one must consider both interactions and disorder to obtain finite and T dependent resistivity. By power counting, the correction to the residual resistivity at low T scales as AT (D+2)/3 near a Z = 3 QPT. We show, however, that A = 0 for a simply connected, convex Fermi surface in 2D, due to hidden integrability of the electron motion. We argue that A > 0 in a two-band (s − d) model and propose this model as an explanation for the observed T (D+2)/3 behavior.

Specific heat of a Fermi system near ferromagnetic quantum phase transition

We calculate the specific heat for an interacting Fermi system near the ferromagnetic phase transition using the Renormalization Group method. The temperature dependence of the specific heat present for dimension D = 3 a logarithmic dependence which shows that the fermionic excitations reaches a non -Fermi behavior. The result is in good agreement with the experimental data obtained recently for N i x P d 1−x alloys.

Study of non-Fermi-liquid behaviour near the ferromagnetic quantum critical point in CePd0.15Rh0.85

Journal of Magnetism and Magnetic Materials, 2007

Recent bulk measurements on CePd 1Àx Rh x alloys indicate a ferromagnetic quantum critical point (FQCP) near the critical composition x c ¼ 0.85. We present here the first results of the spin dynamics near the FQCP in CePd 0.15 Rh 0.85 investigated using inelastic neutron scattering measurements over a wide temperature range between 5 and 260 K. Our study reveals a strong quasielastic scattering between 5 and 260 K, which is nearly temperature independent on the neutron energy loss side, but follows the population factor on the neutron energy gain side. Furthermore, we found a novel E/T scaling behaviour, with the scaling exponent a ¼ 0.6, of the dynamical susceptibility, w(E,T). At low temperatures (below 60 K) the quasielastic linewidth (G) exhibits a linear temperature dependence, which is in agreement with the theoretical prediction for non-Fermi-liquid behaviour near a QCP. We compare the observed scaling behaviour in CePd 0.15 Rh 0.85 near the FQCP with that of systems having an antiferromagnetic QCP or a spin-glass quantum-type critical point.

Marginal breakdown of the Fermi-liquid state on the border of metallic ferromagnetism

Nature, 2008

For the past half century, our understanding of how the interactions between electrons affect the low-temperature properties of metals has been based on the Landau theory of a Fermi liquid 1 . In recent times, however, there have been an increasingly large number of examples in which the predictions of the Fermi-liquid theory appear to be violated 2 . Although the qualitative reasons for the breakdown are generally understood, the specific quantum states that replace the Fermi liquid remain in many cases unclear. Here we describe an example of such a breakdown where the non-Fermi-liquid properties can be interpreted. We show that the thermal and electrical resistivities in high-purity samples of the d-electron metal ZrZn 2 at low temperatures have T and T 5/3 temperature dependences, respectively: these are the signatures of the 'marginal' Fermi-liquid state 3-7 , expected to arise from effective long-range spin-spin interactions in a metal on the border of metallic ferromagnetism in three dimensions 3,5 . The marginal Fermi liquid provides a link between the conventional Fermi liquid and more exotic non-Fermi-liquid states that are of growing interest in condensed matter physics. The idea of a marginal Fermi liquid has also arisen in other contextsfor example, in the phenomenology of the normal state of the copper oxide superconductors 7 , and in studies of relativistic plasmas and of nuclear matter 3,4,6 .

Non-Fermi Behavior of the Itinerant-Electron Ferromagnet near the Quantum Phase Transition Point

Journal of Superconductivity, 2001

We used the Renormalization Group (RG) method in the Hertz–Millis version to study the quantum phase transition of the itinerant-electron ferromagnet. Near the quantum phase transition point the system present a non-Fermi behavior in agreement with the experimental results. The importance of long-range interactions considered by Belitz–Kirkpatrick–Vojta was taken into consideration, showing the importance of the marginal parameters.

Universal behavior of CePd1−x Rh x ferromagnet at the quantum critical point

JETP Letters, 2007

The nature of the non-Fermi liquid (NFL) behavior observed in heavy-fermion (HF) metals is still hotly debated. It is widely believed that the observed behavior is determined by quantum phase transitions that occur at quantum critical points, while the proximity of a system to quantum critical points creates its NFL behavior brought about by the corresponding thermal and quantum fluctuations suppressing quasiparticle excitations . A quantum critical point (QCP) can arise by suppressing the transition temperature

Fermi-liquid instabilities at magnetic quantum phase transitions

Reviews of Modern Physics, 2007

This review discusses instabilities of the Fermi-liquid state of conduction electrons in metals with particular emphasis on magnetic quantum critical points. Both the existing theoretical concepts and experimental data on selected materials are presented; with the aim of assessing the validity of presently available theory. After briefly recalling the fundamentals of Fermi-liquid theory, the local Fermi-liquid state in quantum impurity