Abstract

Fano resonances arise due to quantum mechanical coupling of a discrete state to a degen״ erate continuum.¹ The line shape in optical absorption spectra is characterized by an in״ trinsic broadening of the line, strong asymmetry, and a reduced absorption at one side of the peak falling well below the pure continuum level. The effect is well known in atomic physics but has been scarcely investigated in semiconductors. Intensive theoretical investigations predicted Fano resonances as a general feature of a large variety of low-dimensional semiconductors.² The existence of the coupling has been shown in quantum wells³ and bulk GaAs under a magnetic field.⁴ In the latter system, first results about the dynamics have been published.^5.6

© 1998 Optical Society of America