Resonance selective excitation of terahertz plasma waves in a semiconductor quantum well using two-color laser radiation

A new method of coherent resonance excitation of plasma instability in a 2D quantum well driven by two-color laser radiation due to photoinduced generation of electron-hole pairs is proposed. It is shown that under the resonance condition, where the frequency and wavenumber of the beat wave obey the 2D plasmon dispersion relation, a space-charge wave is excited efficiently. A self-consistent treatment of the problem is presented and the small-signal response of the 2D system in the THz frequency region is found. This new method provides the selective resonance excitation of plasmons, tuning of their frequency, and efficient control of plasma wave parameters crucial for THz semiconductor technology.