The ladder structure of the quasi-energy states of a one-dimensional semiconductor superlattice under combined dc-ac fields has been studied by calculating the absorption spectrum based on the semiconductor Bloch equations. In particular, we investigated the periodic motion of the carriers in a band under an ac field or a dc field. Under ac field with the frequency of ωL, we found periodic motion of ωL, which was very similar to the Bloch oscillation under the a dc field. The ladder structure of quasi-energy states with a ladder spacing ℏωL under an ac field were shown to be the counterparts of the frequency domain of periodic motion. Under combined ac-dc fields, we found the absorption peaks corresponding to the so-called dynamical fractional Stark ladders with energies ∈o + mℏωB + m′ℏωL, where m and m′ are integers and ωB is the Bloch oscillation frequency.
|Number of pages||4|
|Journal||Journal of the Korean Physical Society|
|Publication status||Published - 2001 May 1|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)