Anisotropic spin splitting of the electron ground state in InAs quantum dots

Photoinduced circular dichroism experiments in an oblique magnetic field allow measurements of Larmor precession frequencies, and so give a precise determination of the electron Lande g factor and its anisotropy in self-assembled InAs/GaAs quantum dots emitting at 1.32 eV. In good agreement with recent theoretical results, we measure g perp= 0.397 +_ 0.003 and g par = 0.18 +- 0.02.