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HL: Fachverband Halbleiterphysik
HL 7: Transport properties I
HL 7.4: Vortrag
Montag, 18. März 2024, 15:45–16:00, ER 325
Electrical Conductivity and Carrier Mobility for Strongly Anharmonic Materials from First Principles — •Jingkai Quan1,2, Christian Carbogno1, and Matthias Scheffler1 — 1The NOMAD Laboratory at Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195, Berlin, Germany — 2Max-Planck Institute for the Structure and Dynamics of Matter, Luruper Chausse 149, 22761, Hamburg, Germany
First-principle approaches for describing phonon-limited electronic transport are typically based on many-body perturbation theory and the Boltzmann transport equation, which can be questionable in strongly anharmonic systems. Combining ab initio molecular dynamics (aiMD) simulations and the Kubo-Greenwood (KG) formalism, we investigate a non-perturbative stochastic method to calculate carrier mobilities, which accounts for all orders of anharmonic and vibronic couplings. We implement the KG formula in the highly efficient all-electron code FHI-aims. In particular, we discuss in this talk the definition of carrier mobility in the KG framework and the developed numerical strategies employed to overcome the notoriously slow convergence of the phase-space and Brillouin-zone integrals in crystalline solids. Using strongly anharmonic perovsktie SrTiO3 and BaTiO3, we demonstrate the capabilities and predictive power of the KG approach and investigate the influence of the chosen exchange-correlation functional on the obtained conductivities and mobilities. Eventually, we analyze the observed trends and explain the effects in terms of self-energy shifts and broadenings.
Keywords: Carrier Mobility; Kubo-Greenwood Formula; Anharmonicity; Electronic Transport Property; Electron-Phonon Coupling