Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 68: Transport (Diffusion, conductivity, heat)

MM 68.4: Vortrag

Donnerstag, 15. März 2018, 18:15–18:30, TC 010

electronic transport coefficients from first principles — •zhen-kun yuan, christian carbogno, and matthias scheffler — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6,14195 Berlin

The Kubo-Greenwood formalism has been employed successfully for the first-principles calculation of electrical conductivities at elevated temperature and/or for disordered systems [1]. It relies on ab initio molecular dynamics simulations to include electron-phonon scattering, which is the most important scattering mechanism for electronic transport in bulk materials. However, this approach suffers from severe finite-size effects for crystalline solids close to room temperature, since accounting for the dominant scattering with long-wavelength phonons would require extremely large supercells. In this work, we propose possible strategies to overcome this limitation. In particular, we assess to which extent the asymptotically exact extrapolation scheme [2] that we recently developed to correct for finite-size effects in the calculation of vibrational thermal conductivities can be extended to electronic transport. To this end, ab initio calculations are performed both for direct (GaAs) and indirect (Si) semiconductors and the obtained results are compared to the existing experimental and theoretical data [3].

[1] M. French and T. R. Mattsson, Phys. Rev. B 90, 165113 (2014).

[2] C. Carbogno, R. Ramprasad, and M. Scheffler, Phys. Rev. Lett. 118, 175901 (2017).

[3] J. Zhou, B. Liao, and G. Chen, Semicond. Sci. Technol. 31, 043001 (2016).