Ultrafast Relaxation of Coherent Control Photocurrent in AlGaAs/GaAs Multi Quantum Wells

We theoretically and experimentally study the ultrafast dynamics of coherent control photocurrent in AsGaAs/GaAs multi quantum wells at room temperature. A ballistic photocurrent relaxation time of ~200 fs is deduced based on the theory of density matrix and is evidenced with the three-colour femtosecond pump–probe measurements.