Excitonic dephasing in semimagnetic semiconductors

Abstract

The presence of magnetic ions in a dilute semiconductor quantum well is shown to decrease dramatically the low-temperature excitonic dephasing time measured by transient four-wave mixing. The decrease is associated with the magnetic nature of the material. Surprisingly, the application of a magnetic field does not significantly change the dephasing time, which indicates that there must exist a fast dephasing mechanism in addition to the spin–spin interactions responsible for magnetic polaron formation.