Theoretical studies of the effects of a magnetic field on excitonic nonlinear optical properties of quantum wires

A. Balandin, S. Bandyopadhyay
1996 Physical Review B (Condensed Matter)  
The magnetic-field dependence of the third-order excitonic nonlinear susceptibility (3) in a quantum wire is explored within the rotating wave approximation. Both the real and imaginary parts of (3) , arising from population saturation of the excitonic state under optical pumping, are calculated for a GaAs wire as a function of magnetic field and pump-probe detuning frequencies. The imaginary part of (3) exhibits a negative peak associated with the bleaching of the excitonic resonance and a
more » ... tive, broad, off-resonance absorption peak associated with biexciton formation. The amplitude, line shape, and spectral frequency of both these peaks can be modulated by a magnetic field which indicates the possibility of using such a field to probe the mechanism underlying optical nonlinearity in a quantum wire. Furthermore, the field can also be used to tune the optical nonlinearity over a range of frequencies which has device applications.
doi:10.1103/physrevb.54.5721 pmid:9986536 fatcat:xxtkwct4nrcprhdobd3rm3g3r4