LASER-INDUCED SUPPRESSION OF ELECTRON-TUNNELING IN A BIASED ASYMMETRIC DOUBLE-QUANTUM-WELL

Laser-induced suppression of electron tunneling in a biased asymmetric double-quantum-well structure is numerically studied based on the Mar koff master equation. A pump pulse is used to prepare initially the el ectronic wave packet which is irradiated by a cw laser. It is shown th at if the bias voltage is adjusted to align the upper two electronic s tates in the narrow well and the wide well, suppression can occur befo re dephasing is complete. An analytical expression for the time evolut ion of the wave packet is derived by a degenerate-two-level model to g ive a qualitative interpretation to the origin of the electron localiz ation.