Optical spin initialization and nondestructive measurement in a quantum dot molecule.
The spin of an electron in a self-assembled InAs/GaAs quantum dot molecule is optically prepared and measured through the trion triplet states. A longitudinal magnetic field is used to tune two of the trion states into resonance, forming a superposition state through asymmetric spin exchange. As a result, spin-flip Raman transitions can be used for optical spin initialization, while separate trion states enable cycling transitions for nondestructive measurement. With two-laser transmission spectroscopy we demonstrate both operations simultaneously, something not previously accomplished in a single quantum dot.
Kim
Danny
D
Naval Research Laboratory, 4555 Overlook Ave, SW, Washington DC 20375, USA.
Economou
Sophia E
SE
Bădescu
Stefan C
SC
Scheibner
Michael
M
Bracker
Allan S
AS
Bashkansky
Mark
M
Reinecke
Thomas L
TL
Gammon
Daniel
D