Dynamical simulation of field emission in nanostructures

An efficient computational scheme based on the first-principles pseudopotential method is proposed for the electron emission from nanostructures under an applied electric field. The emission rate of the electron through the potential barrier is calculated by integrating the time-dependent Schr\"odinger equation for the states residing initially inside the emitter. Our approach takes into account the three-dimensional feature of the nanostructure as well as the realistic self-consistent potential. We have applied this method to the field emission of carbon nanotubes. The calculated emission currents are in good agreement with experimental data and exhibit strong dependence on the spatial distributions of the electronic wave functions.