Abstract
We investigate the probe absorption properties in an asymmetric coupled double quantum-well structure for both the transient and steady-state processes. Beyond the rotating-wave approximation, we directly simulate the transient dynamics with the density-matrix equations. The probe absorption is found to be completely eliminated under the condition of two-photon resonance, without requiring the one-photon resonance condition. More interestingly, our results show that the absorption properties can be tuned by changing the tunnelling barrier. © 2009 IOP Publishing Ltd.