Nonlinear ac transport and local fields in quantum wires

Nonlinear frequency-dependent transport in a single-channel quantum wire with a potential barrier in the presence of electron interaction is investigated. The bosonization method for treating the electron-electron interaction is used. The polarization and tunneling currents are evaluated in the weak tunneling region. Harmonic generation is studied. The corresponding longitudinal and transverse electromagnetic fields are evaluated. The importance of screening and local fields is discussed. It is concluded that apart from the influence of induced external screening currents, local longitudinal field corrections are automatically included if the interaction between electrons is taken into account exactly.