  Polarization-resolved single dot spectroscopy performed on (211)B InAs/GaAs
quantum dots reveals that the fine structure splitting of the excitonic levels
in these dots is much lower compared to the usual (100)-grown InAs dots.
Time-resolved measurements confirm the high oscillator strength of these dots,
and thus their good quantum efficiency at 4 K, comparable with that of (100)
InAs/GaAs dots. Last, photon correlation measurements demonstrate single photon
emission out of the excitonic optical transition of these dots. All these
features make this novel dot system very promising for implementing solid-state
entangled photon sources.
