Sunday, February 12, 2012

Optically Erasing Disorder in Semiconductor Microcavities with Dynamic Nuclear Polarization

Liew, T.C.H. and V. Savona, Optically Erasing Disorder in Semiconductor Microcavities with Dynamic Nuclear Polarization. Phys. Rev. Lett., 2011. 106(14): p. 146404.


The mean squared value of the photonic disorder is found to be reduced by a factor of 100 in a typical GaAs based microcavity when exposed to a circularly polarized continuous wave optical pump without any special spatial patterning. Resonant excitation of the cavity mode excites a spatially nonuniform distribution of spin-polarized electrons, which depends on the photonic disorder profile. Electrons transfer spin to nuclei via the hyperfine contact interaction, inducing a long-living Overhauser magnetic field able to modify the potential of exciton polaritons.