Electron-phonon interaction and lattice thermal conductivity from metals to 2D Dirac crystals: a review.

Electron-phonon (e-ph) coupling governs electrical resistivity, hot-carrier cooling, heat flow, and critically, thermal transport in solids. Recent first-principles calculations now predict e-ph-limited thermal conductivity fromd-band metals and wide-band-gap semiconductors to two-dimensional (2D) Dirac crystals without empirical parameters. In bulk metals,ab-initiolifetimes show that phonons, though secondary, still carry up to 40%of the heat once e-ph scattering is included. We next survey coupled Boltzmann frameworks, exemplified byelphbolt, that capture mutual drag and ultrafast non-equilibrium in semiconductors; their results for Si, GaAs, and MoS2match the time-domain thermo-reflectance andisotope-controlled data within experimental error. For 2D Dirac crystals, mirror symmetry, scarrier density, strain, and finite size rearrange the scattering hierarchy: flexural (ZA) modes dominate pristine graphene yet become the main resistive branch in nanoribbons onceσhsymmetry is broken. At low Fermi energies whereEF≪kBT, the standard three-particle decay is partially cancelled, elevating-particle processes and necessitating dynamically screened, higher-order theory. Throughout, we identify the microscopic levers such as the electronic density of states, phonon frequency, deformation potential, and Fröhlich coupling, and show how doping, strain, or dielectric environment can tune e-ph damping. We conclude by outlining Open challenges such as: developing femtosecond-resolved, coupled e-ph solvers, solving the full mode-to-mode Peierls-Boltzmann equation with four-particle terms, embedding correlated-electron methods (GW, dynamical mean-field theory, hybrid functionals) in e-ph workflows, implementing fully non-local, frequency-dependent screening for van-der-Waals stacks, and leveraging higher-order e-ph coupling and symmetry breaking to realize phononic thermal diodes and rectifiers. Solving these challenges will elevate e-ph theory from a diagnostic tool to a predictive, parameter-free platform that links symmetry, screening, and many-body effects to heat and charge transport in next-generation electronic, photonic, and thermoelectric devices.