Ab initio determination of effective electron-phonon coupling factor in copper

Multiscale modeling of femtosecond laser irradiation on copper film with electron thermal conductivity from ab initio calculation

By combining ab initio quantum mechanics calculation and Drude model, electron temperature and lattice temperature dependent electron thermal conductivity is calculated and implemented into a multiscale model of laser material interaction, which couples the classical molecular dynamics and two-temperature model. The results indicated that the electron thermal conductivity obtained from ab initio calculation leads to faster thermal diffusion than that using the electron thermal conductivity from empirical determination, which further induces deeper melting region, larger number of density waves…

Ab initio theory of coherent phonon generation by laser excitation

We show that time-dependent density functional theory (TDDFT) is applicable to coherent optical phonon generation by intense laser pulses in solids. The two mechanisms invoked in phenomenological theories, namely impulsively stimulated Raman scattering and displacive excitation, are present in the TDDFT. Taking the example of crystalline Si, we find that the theory reproduces the phenomena observed experimentally: dependence on polarization, strong growth at the direct band gap, and the change of phase from below to above the band gap. We conclude that the TDDFT offers a predictive ab initio f…

Boosting the efficiency of ab initio electron-phonon coupling calculations through dual interpolation

The coupling between electrons and phonons in solids plays a central role in describing many phenomena, including superconductivity and thermoelecric transport. Calculations of this coupling are exceedingly demanding as they necessitate integrations over both the electron and phonon momenta, both of which span the Brillouin zone of the crystal, independently. We present here an ab initio method for efficiently calculating electron-phonon mediated transport properties by dramatically accelerating the computation of the double integrals with a dual interpolation technique that combines maximally…

Perturbo: a software package for ab initio electron-phonon interactions, charge transport and ultrafast dynamics

Perturbo is a software package for first-principles calculations of charge transport and ultrafast carrier dynamics in materials. The current version focuses on electron-phonon interactions and can compute phonon-limited transport properties such as the conductivity, carrier mobility and Seebeck coefficient. It can also simulate the ultrafast nonequilibrium electron dynamics in the presence of electron-phonon scattering. Perturbo uses results from density functional theory and density functional perturbation theory calculations as input, and employs Wannier interpolation to reduce the computat…

InterPhon: Ab initio Interface Phonon Calculations within a 3D Electronic Structure Framework

This work provides the community with an easily executable open-source Python package designed to automize the evaluation of Interfacial Phonons (InterPhon). Its strategy of arbitrarily defining the interfacial region and periodicity alleviates the excessive computational cost in applying ab initio phonon calculations to interfaces and enables efficient extraction of interfacial phonons. InterPhon makes it possible to apply all of the phonon-based predictions that have been available for bulk systems, to interfacial systems. The first example, in which this package was applied to InAs surfaces…

电子序诱导晶格动力学对称性破缺的通用第一性原理框架

General ab initio framework for electronic-order-induced lattice-dynamics symmetry breaking

提出基于分子贝里曲率理论的第一性原理框架，描述电子序驱动的晶格动力学对称性破缺，在Co3Sn2S2中定量复现实验声子劈裂，并预测多种候选材料。