Title:Oral : Exploring electron-phonon interactions in diamond and silicon: insights from spectral analysis

This study explores the electron-phonon interactions in diamond and silicon, two nonpolar crystals exploited for their spectroscopic, transport and optical properties. Despite their nonpolar nature, these materials exhibit spectral features due to the formation of polarons—quasi-particles that emerge from the interaction between electrons and lattice vibrations. To analyze the many-body spectral function in these materials, we employ both the Dyson-Migdal approach and the cumulant expansion method.[1] The latter, which incorporates higher-order electron-phonon interactions, offers more accurate quantitative agreement with experimental satellite peaks, particularly near the conduction and valence band edges. In diamond, the spectral function reveals a plateau structure,[2] similar to but distinct from the satellite peaks typically seen in polar Fröhlich systems. By contrast, silicon displays more pronounced satellite peaks due to the closer spacing of its phonon frequencies in comparison to diamond. We also explore the temperature dependence of these spectral functions and investigate the effects of p- and n-type doping in silicon. As doping levels increase, we observe a broadening of the quasiparticle peak. This detailed study sheds light on the complex behaviors of electron-vibration interactions in diamond and silicon, their spectroscopic and electronic properties, and the range and nature of the polaronic interaction.

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[1] J. P. Nery, P. B. Allen, G. Antonius, L. Reining, A. Miglio and X. Gonze Phy. Rev. B 97,115145 (2018)

[2] J. C. Abreu, J. P. Nery, M. Giantomassi, X. Gonze and M. J. Verstraete Phys. Chem. Chem. Phys. 24, 12580 (2022)