FINITE-WAVE VECTOR EFFECT OF PLASMON DISPERSION ON CRITICAL TEMPERATURE IN La1.85 Sr0.15 CuO4

Samnao Phatisena; Nouphy Hompanya

Authors

Samnao Phatisena School of Physics, Institute of Science, Suranaree University of Technology, Nakhonratchasima
Nouphy Hompanya Department of Physics, Faculty of Science, National University of Lao, Vientiane, Laos

Keywords:

Plasmon exchange model, finite-wave vector effect, acoustic plasmons, critical temperature

Abstract

Using the plasmon exchange model in the framework of the Eliashberg theory for strong-coupling superconductors, the critical temperature of La1.85 Sr0.15 CuO4 has been calculated. The finite-wave vector effect on acoustic plasmon dispersion has been included in the expression for the effective interaction between charge carriers. This effect is shown to enhance the critical temperature significantly as compared with the result without this term. The critical temperature is sensitively dependent on the spacer dielectric constant εM which is not known precisely. The Coulomb repulsion strength μ∗ has been tested around the commonly used value of 0.1. It is found that their proper values of them are εM ≈ 8.0 and μ∗ ≈ 0.1.

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