1 research outputs found
Direct Measurement of Ballistic and Diffusive Electron Transport in Gold
We experimentally show that the ballistic length of hot
electrons
in laser-heated gold films can exceed ∼150 nm, which is ∼50%
greater than the previously reported value of 100 nm inferred from
pump–probe experiments. We also find that the mean free path
of electrons at the peak temperature following interband excitation
can reach upward of ∼45 nm, which is higher than the average
value of 30 nm predicted from our parameter-free density functional
perturbation theory. Our first-principles calculations of electron–phonon
coupling reveal that the increase in the mean free path due to interband
excitation is a consequence of drastically reduced electron–phonon
coupling from lattice stiffening, thus providing the microscopic understanding
of our experimental findings