Novel approach to Fano resonance of excitons in semiconductor quantum wells

A new approach to Fano resonance of excitons in quantum-confined systems is presented based on the 4 x 4 Luttinger Hamiltonian. This method, consisting of two stages, namely, the adiabatic expansion and the R-matrix propagation, allows to implement high-resolution calculations of Fano profiles having natural spectral widths without any empirical broadening parameter which is indispensable in conventional methods. As a demonstration, this approach is applied to Fano resonance of an exciton in a wide quantum well, where hole-subband mixing is substantial and a complicated energy-structure is expected. Resulting spectral profiles show rich fine structures due to overlap with adjacent resonances and the hole-subband mixing.