Dispersion relations of hybrid states

To calculate the dispersion relation of the hybrid excitons we approximate the WE energy by a parabola with the in-plane effective mass mw = me + rrih, being the electron (hole) mass, and neglect the FE dispersion since the typical masses are (5-100) mq  

We will measure all energies with respect to Ew (0). The dispersion of the hybrid states (13.3) can be written as 

To perform numerical estimates we choose the following values of the parameters. For the IQW those representative of II-VT semiconductor (e.g. ZnSe/ZnCdSe) quantum wells are taken (20) e = = 6, dvc/aF O.le (which corresponds to 

The dispersion Eu (k) of the upper and lower hybrid exciton branches (solid lines) and that of the unperturbed Frenkel and Wannier excitons (dotted lines). The weight of the FE component in the lower branch yb(fc) 2 is shown by the dashed line. The parameters are the same as in Fig. 13.2 (mw = 0.7 mo), the detuning S = 10 meV (from (13)). 

For our parameters dcr 16 meV. For large negative values of 6 C —rmax the lower branch dispersion at k C y/2mwS/h2 may be approximated by 

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