SKM 2023 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 36: Transport properties

HL 36.3: Talk

Thursday, March 30, 2023, 10:00–10:15, POT 151

Rapid Electronic Transport Predictions via the Kubo-Greenwood Formalism — •Florian Fiebig, Matthias Scheffler, and Christian Carbogno — The NOMAD Laboratory at the FHI of the Max-Planck-Gesellschaft and IRIS-Adlershof of the Humboldt-Universität zu Berlin

For the first-principles evaluation of electronic heat and charge transport coefficients, the Kubo-Greenwood (KG) formalism [1] represents a more general and accurate alternative to perturbative approaches, [2] since it naturally incorporates all orders of anharmonic and vibronic effects. In practice, however, KG calculations come with a prohibitive computational cost, since ordered crystalline materials typically require both dense reciprocal-space k-grids for the electronic degrees of freedom and large real-space supercells for the vibrational ones. In this work, we propose an adaptive, KG-specific scheme for the k-space sampling that alleviates this issue. It enables the use of very coarse k-grids during the self-concistency cycle, whereas very dense k-grids are used for the evaluation of the KG formula, but only for those Brillouin-zone regions that contribute to the conductivities. As demonstrated for Silicon, this massively reduces the involved computational cost, and hence paves the way towards affordable, fully anharmonic predictions of electronic heat and charge transport coefficients.

[1] B. Holst, M. French, and R. Redmer, Phys. Rev. B 83, 235120 (2011).

[2] S. Poncé, E. R. Margine, and F. Giustino, Phys. Rev. B 97, 121201 (2018).