HARMONIC-GENERATION BY A ONE-DIMENSIONAL CONDUCTOR - EXACT RESULTS

The exact harmonic-generation (HG) spectrum is obtained analytically for a one-band one-dimensional conductor for both ac and ac + dc external fields. it is shown that even and odd harmonics can be created and controlled depending on the initial-state conditions and the field amplitudes E. The HG spectrum forms a single plateau with a cutoff defined by a maximum HG order N(m) corresponding to the maximum energy acquired by the electron in the laser field. This maximum energy corresponds to single transfer between neighboring sites, i.e., N(m)=eEa/homegaBAR, where a is the lattice constant and omega the field frequency.