Fermi liquid model

It was shown then that all these observed features can be described self-consistently by Fermi-liquid model for quasiparticles in clean d-wave superconductor with resonant intralayer scattering [14]. The superconducting gap is expressed as A([Pg.185]

Fig. 10b shows a comparison of our data with the microwave results [18]. The origin of the peak of oab(T) has been widely discussed as a result of a d-wave symmetry of the OP in BSCCO and YBCO. In particular, in a d-wave Fermi-liquid model it was shown that at low temperatures oab grows with temperature as [27] o(m—>0,T) = <70o (1 + fl2), where Ooo is a universal inplane conductivity introduced by Lee [28], Ooo = n e2 /(n mabAo) with mab the effective quasiparticle in-plane mass. 

The DDM is not expected to lead to the "final" theory of the nucleus. (That would probably be closer to the HFB model mentioned above, or the recently developed Relativistic Fermi Liquid model [ANA83], or something very different.) Hence, no effort is made to find the "best" parameters for each nuclear region, as is done in most of the currently popular models. Instead, all model parameters are given fixed strengths and Z-A-dependences. There are no local parameters. This provides a perfect excuse for not obtaining perfect agreement with the experimental data ... 

Many features of the data may be conveniently discussed in terms of theoretical descriptions based on the Fermi-liquid model. We shall start by considering the shape of the low-temperature response, for which the analytic function given by Kuramoto and Miiller-Hartmann (1985) is useful. This is followed by a discussion of some more general aspects arising from a consideration of the Wilson ratio (Wilson 1975, Lustfeld and Bringer 1978). 

The application of a pure itinerant model (such as the Stoner-Wohlfarth or the Fermi-liquid model) is limited in R-3d compounds. Such models, if they are valid, are confined to systems where R possesses no moment, e.g. Y, Lu, Zr. 

The Fermi liquid models 105 3.4.3. Results of model calculation 133... 

There are three broad versions of Fermi liquid models in the literature, each is applicable for specific problems. The one-band model has provided the first understanding of the low-temperature thermodynamic and transport properties. The interpretation of inelastic neutron scattering data requires a two-band hybridization model. The band model based on the local-density functional approximation is by far the most elaborate noninteracting Fermi fluid model. We will discuss only the basic principle of this approach because the details appear elsewhere in this volume. 

In the next review (chapter 111), S.H. Liu examines phenomenological approaches to heavy-fermion and mixed-valence materials. He notes that there are two basic approaches to understanding these phenomena the Fermi-liquid models, which are applicable at low temperatures, and the spin fluctuation models, which work well for describing high-temperature properties and behaviors. At the present time Liu concludes that the field is still wide open before we come to even a reasonable understanding of anomalous f-electron behaviors. 

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