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arXiv · 1206.0623

Microscopic mechanisms for the Fermi-liquid behavior of Nb-doped strontium titanate

S. N. Klimin·J. Tempere·D. van der Marel·J. T. Devreese
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Abstract

The relaxation rate in Nb-doped strontium titanate involving different scattering channels is investigated theoretically. It is demonstrated that the total relaxation rate in SrTiO_{3} is provided mainly by two mechanisms. The Baber electron-electron scattering with participation of both Coulomb and phonon-mediated electron-electron interactions provides the T^{2}-dependence of the relaxation rate. The scattering on the potential landscape caused by impurities is responsible for the residual relaxation rate at low temperatures. A good agreement with experiment is achieved accounting for all phonon branches in strontium titanate, both the optical and acoustic phonons. It is shown that the effective electron-electron interaction can be attractive in strontium titanate, and provides superconductivity at low temperatures and Fermi-liquid response in a wide range of temperatures. Thus our microscopic model supports the notion that superconductivity and Fermi-liquid properties of n-type SrTiO_{3} have a common origin.

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S. N. Klimin, J. Tempere, D. van der Marel, J. T. Devreese. 2012-06-04. Microscopic mechanisms for the Fermi-liquid behavior of Nb-doped strontium titanate. https://doi.org/10.1103/physrevb.86.045113

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