Ultralong dephasing time in InGaAs quantum dots

Phys Rev Lett. 2001 Oct 8;87(15):157401. doi: 10.1103/PhysRevLett.87.157401. Epub 2001 Sep 20.


We measure a dephasing time of several hundred picoseconds at low temperature in the ground-state transition of strongly confined InGaAs quantum dots, using a highly sensitive four-wave mixing technique. Between 7 and 100 K the polarization decay has two distinct components resulting in a non-Lorentzian line shape with a lifetime-limited zero-phonon line and a broadband from elastic exciton-acoustic phonon interactions.