Article

Ultrashort electromagnetic pulse control of intersubband quantum well transitions

Nanoscale Research Letters (Impact Factor: 2.48). 08/2012; 7(1):478. DOI: 10.1186/1556-276X-7-478
Source: PubMed

ABSTRACT We study the creation of high-efficiency controlled population transfer in intersubband transitions of semiconductor quantum wells. We give emphasis to the case of interaction of the semiconductor quantum well with electromagnetic pulses with duration few cycles and even a single cycle. We numerically solve the effective nonlinear Bloch equations for a specific double GaAs/AlGaAs quantum well structure, taking into account the ultrashort nature of the applied field, and show that high-efficiency population inversion is possible for specific pulse areas. The dependence of the efficiency of population transfer on the electron sheet density and the carrier envelope phase of the pulse is also explored. For electromagnetic pulses with duration several cycles we find that the change in the electron sheet density leads to a very different response of the population in the two-subbands to pulse area. However, for pulses with duration equal to or shorter than three cycles we show that efficient population transfer between the two subbands is possible, independent of the value of electron sheet density, if the pulse area is pi.

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