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arXiv · 1003.1003

Many-body large polaron optical conductivity in SrTi$_{1-x}$Nb$_x$O$_3$

J. T. Devreese·S. N. Klimin·J. L. M. van Mechelen·D. van der Marel
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Abstract

Recent experimental data on the optical conductivity of niobium doped SrTiO$_{3}$ are interpreted in terms of a gas of large polarons with effective coupling constant $α_{eff}\approx2$. The {theoretical approach takes into account} many-body effects, the electron-phonon interaction with multiple LO-phonon branches, and the degeneracy and the anisotropy of the Ti t$_{2g}$ conduction band. {Based on the Fröhlich interaction, the many-body large-polaron theory} provides an interpretation for the essential characteristics, except -- interestingly -- for the unexpectedly large intensity of a peak at $\sim130$ meV, of the observed optical conductivity spectra of SrTi$_{1-x}$Nb$_{x}$O$_{3}$ \textit{without} any adjustment of material parameters.

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J. T. Devreese, S. N. Klimin, J. L. M. van Mechelen, D. van der Marel. 2010-03-04. Many-body large polaron optical conductivity in SrTi$_{1-x}$Nb$_x$O$_3$. https://doi.org/10.1103/physrevb.81.125119

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