Abstract
We describe a new approach to compute the electron-phonon self-energy and carrier mobilities in semiconductors. Our implementation does not require a localized basis set to interpolate the electron-phonon matrix elements, with the advantage that computations can be easily automated. Scattering potentials are interpolated on dense $\mathbf{q}$ meshes using Fourier transforms and ab initio models to describe the long-range potentials generated by dipoles and quadrupoles. To reduce significantly the computational cost, we take advantage of crystal symmetries and employ the linear tetrahedron method and double-grid integration schemes, in conjunction with filtering techniques in the Brillouin zone. We report results for the electron mobility in Si, GaAs, and GaP obtained with this new methodology.
Highlights
Electron-phonon (e-ph) interactions play an important role in various physical phenomena [1] such as conventional phonon-mediated superconductivity [2,3,4,5,6,7], phonon-assisted light absorption [8,9,10], temperature-dependent band structures, zero-point renormalization of the band gap in semiconductors [11,12,13,14,15], and thermal [16,17,18] and electrical conductivities [19,20,21,22,23,24,25,26,27,28]
We present an efficient method based on plane waves and Bloch states for the computation of the e-ph self-energy and carrier mobilities in the self-energy relaxation time approximation
Our approach takes advantage of symmetries and advanced integration techniques such as the linear tetrahedron and double-grid methods to achieve accurate results with a computational cost that is competitive with state-of-theart implementations based on localized orbitals
Summary
Electron-phonon (e-ph) interactions play an important role in various physical phenomena [1] such as conventional phonon-mediated superconductivity [2,3,4,5,6,7], phonon-assisted light absorption [8,9,10], temperature-dependent band structures, zero-point renormalization of the band gap in semiconductors [11,12,13,14,15], and thermal [16,17,18] and electrical conductivities [19,20,21,22,23,24,25,26,27,28]. The generation of maximally localized Wannier functions (MLWFs) is not always trivial and non-negligible effort may be needed to obtain an appropriate set of MLWFs spanning the energy region of interest.. The generation of maximally localized Wannier functions (MLWFs) is not always trivial and non-negligible effort may be needed to obtain an appropriate set of MLWFs spanning the energy region of interest.1 This is especially true for systems whose band structure cannot be interpreted in terms of standard chemistry concepts, or when high-energy states must be included to compute the real part of the SE whose convergence with the number of empty states is notoriously slow [37]. It is not surprising that recent works proposed to replace Wannier functions with atomic orbitals [38]
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