Intersubband laser coupled three-level asymmetric quantum wells: new dynamics of quantum interference

Abstract

The improved density-functional theory is employed to obtain the eigenstates of electrons in an asymmetric quantum well. On the basis of calculated eigenstates, the semiconductor Bloch equations are used to calculate the transient density matrix when a pulsed intersubband laser coupling is applied to the system. The new dynamics of the individual absorption peaks is analyzed for the first time by use of a self-consistent-field theory. Based on this, the time-averaged optical spectrum is calculated to show the coherent-transition-induced quantum interference in the system. The new phenomena of probe-field amplification is observed, and the threshold laser intensity for observing it is given.