Excitons and their electromagnetic interactions

Ka‐Di Zhu, Wai-Sang Li

Using the bosonic exciton approximation, we show that there exists electromagnetically induced transparency (EIT) in an organic quantum well which includes the interaction of charge-transfer excitons and phonons. The numerical results indicate that the strong exciton-phonon interaction plays a key role in the generation of the EIT. Without the exciton-phonon coupling, the EIT will disappear immediately. Ultraslow light effects are also discussed in this system.

Hideki Gotoh, Hidehiko Kamada, Tadashi Saitoh +2 more

The absorption properties of an exciton-biexciton system are examined for quantum dots by single-dot photoluminescence spectroscopy. A strong exciton-biexciton coherent interaction causes electromagnetically induced transparency-like nonlinear exciton absorption.

Valentin Walther, P. Grünwald, Thomas Pohl

Highly excited Rydberg states of excitons in Cu_{2}O semiconductors provide a promising approach to explore and control strong particle interactions in a solid-state environment. A major obstacle has been the substantial absorption background that stems from exciton-phonon coupling and lies under the Rydberg excitation spectrum, weakening the effects of exciton interactions. Here, we demonstrate that two-photon excitation of Rydberg excitons under conditions of electromagnetically induced transparency (EIT) can be used to control this background. Based on a microscopic theory that describes the known single-photon absorption spectrum, we analyze the conditions under which two-photon EIT permits separating the optical Rydberg excitation from the phonon-induced absorption background, and even suppressing it entir7ely. Our findings thereby pave the way for the exploitation of Rydberg blockade with Cu_{2}O excitons in nonlinear optics and other applications.

Claus F. Klingshirn