Compressibility and density response function in disordered systems

Takayuki Sota, K. Suzuki

    Research output: Contribution to journalArticle

    2 Citations (Scopus)

    Abstract

    We give a detailed study on the compressibility and the density response function in a disordered system which has a single-band or single-valley structure with a spherical energy surface, in the absence of external magnetic fields. In analysis we use a diagrammatic method which gets the benefit of Finkelsteins renormalization scheme and can be applied easily to cases where there are interactions between particles and other elementary excitations. It is shown that in obtaining the relation between the compressibility and the density response function in the static and the long-wavelength limits, 0 and q0, we need diagrams which are different from familiar electron-hole bubble diagrams and which have not been discussed so far. The following fact is ascertained: The interaction among particles involving thermal diffusion processes does not contribute to the compressibility as a whole, but gives a significant influence on the density response function in the dynamical case, where both the external frequency and wave vector are finite, provided that a typical excitation energy due to the thermal fluctuation is much larger than that due to the external disturbance. Furthermore, it is shown that as a result of the particle number conservation law there should exist no term which prevents the divergence of the electron-hole diffusion propagator in the limits 0 and q0.

    Original languageEnglish
    Pages (from-to)2464-2472
    Number of pages9
    JournalPhysical Review B
    Volume40
    Issue number4
    DOIs
    Publication statusPublished - 1989

    Fingerprint

    Compressibility
    Density (specific gravity)
    compressibility
    Particle interactions
    diagrams
    particle diffusion
    Thermal diffusion
    Electrons
    Excitation energy
    thermal diffusion
    elementary excitations
    conservation laws
    Interfacial energy
    surface energy
    valleys
    Conservation
    divergence
    disturbances
    bubbles
    interactions

    ASJC Scopus subject areas

    • Condensed Matter Physics

    Cite this

    Compressibility and density response function in disordered systems. / Sota, Takayuki; Suzuki, K.

    In: Physical Review B, Vol. 40, No. 4, 1989, p. 2464-2472.

    Research output: Contribution to journalArticle

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