Coherent double-pulse control of quantum beats in a coupled quantum well

Analytical and numerical solutions for coherent excitations of quantum beats in a coupled quantum well by two phase-locked optical pulses are shown using the density-matrix formulation. It is demonstrated that active control of terahertz radiation due to charge oscillations caused by quantum beats in a coupled-quantum-well structure is possible using two-femtosecond optical pulses with a time delay shorter than the exciton dephasing time. Our theoretical results agree very well with experimental observations.