Determination of the electron-phonon coupling constant in tungsten

We used two methods to determine the effective electron-phonon coupling constant (G₀) in tungsten. Our first principles calculations predict G₀ = 1.65 × 10¹⁷W m^-3 K^-1. The temporal decay of the femtosecond-resolution optical reflectivity for a (100) surface of bulk W was measured using a pump-probe scheme and analysed using ab initio parameterised two temperature model, which includes both the effects of the electron-phonon coupling and thermal conduction into bulk. This analysis gives G₀ = 1.4(3) × 10¹⁷W m^-3 K ^-1, in good agreement with the theoretical prediction. The described effective method of calculating and measuring G₀ in bulk materials can be easily extended to other metals.