Multiparticle effects in nonequilibrium electron tunneling and field emission

We investigate energy resolved electric current from various correlated host materials under out-of-equilibrium conditions. We find that, due to a combined effect of electron-electron interactions, nonequilibrium and multiparticle tunneling, the energy resolved current is finite even above the Fermi edge of the host material. In most cases, the current density possesses a singularity at the Fermi level revealing manifestations of correlation effects in electron tunneling. By means of the Keldysh nonequilibrium technique, the current density is calculated for one-dimensional interacting electron systems and for two-dimensional systems, both in the pure limit and in the presence of disorder. We then specialize to the field emission and provide a comprehensive theoretical study of this effect in carbon nanotubes.