Intraexcitonic coherent optics


Intraexcitonic coherent optics

Teich, M.; Wagner, M.; Stehr, D.; Schneider, H.; Helm, M.; Chatterjee, S.; Gibbs, H.; Khitrova, G.

A fundamental problem in light-matter interaction is the coupling of an intense, monochromatic electromagnetic wave with a quantum mechanical two-level system. One effect related to this is the Autler-Townes or AC Stark effect. Originally observed and described in molecular spectroscopy the effect refers to a splitting of an energy level that is resonantly coupled via intense radiation to an adjacent level, i.e. the states get ”dressed” by the light-matter interaction. We investigate this effect using a free-electron laser (FEL) driven intra-excitonic transition between the heavy-hole 1s and 2p states in a semiconductor multiple quantum well. We have observed distinct intensity- and wavelength dependent Rabi sidebands of the 1s exciton line when the FEL was tuned around the 1s-2p transition. We also present measurements at higher electric fields exploring the regime beyond the rotating-wave approximation (RWA). Theoretical calculations support the understanding of the underlying processes which is especially interesting for the regime beyond the RWA. Also temperature-dependent measurements have been done and a clear Rabi-sideband behavior is observable up to 200 K where the thermal energy already exceeds the exciton binding energy by a factor of 1.7.

Keywords: Quantum wells; Excitons; THz; FEL

Related publications

  • Poster
    Free-Electron Lasers: From Fundamentals to Applications, 10.-13.04.2012, Bad Honnef, Germany

Permalink: https://www.hzdr.de/publications/Publ-17028
Publ.-Id: 17028