Figure 6
Energy spectra and temporal profiles simulated by the transient thermionic emission model.
(a) Energy spectra for different electron velocity reduction factors CES for ballistic transport and (b) corresponding temporal profiles of the electron emission. (c) Electron distribution function for various times calculated with CES = 0 (solid curves) and CES = 1 (dashed curves), where the time zero is defined when the maximum of the carrier envelope of the laser pulse is at the center of the tip apex. After 100 fs, electron distribution function reaches thermal equilibrium and is reasonably fitted by a Fermi-Dirac distribution function as indicated by blue curves. The inset of (b) shows evolution of effective temperature extracted from electron distribution functions after 100 fs.
